Interstate 70 (I-70) is a transcontinental
Interstate Highway
The Dwight D. Eisenhower National System of Interstate and Defense Highways, commonly known as the Interstate Highway System, or the Eisenhower Interstate System, is a network of controlled-access highways that forms part of the National Hi ...
in the United States, stretching from
Cove Fort, Utah
Cove Fort is a fort, unincorporated community, and historical site located in Millard County, Utah. It was founded in 1867 by Ira Hinckley (the paternal grandfather of Gordon B. Hinckley) at the request of Brigham Young. One of its distincti ...
, to
Baltimore, Maryland
Baltimore is the List of municipalities in Maryland, most populous city in the U.S. state of Maryland. With a population of 585,708 at the 2020 United States census, 2020 census and estimated at 568,271 in 2024, it is the List of United States ...
. In
Colorado
Colorado is a U.S. state, state in the Western United States. It is one of the Mountain states, sharing the Four Corners region with Arizona, New Mexico, and Utah. It is also bordered by Wyoming to the north, Nebraska to the northeast, Kansas ...
, the highway traverses an east–west route across the center of the state. In western Colorado, the highway connects the metropolitan areas of
Grand Junction and
Denver
Denver ( ) is a List of municipalities in Colorado#Consolidated city and county, consolidated city and county, the List of capitals in the United States, capital and List of municipalities in Colorado, most populous city of the U.S. state of ...
via a route through the
Rocky Mountains
The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in great-circle distance, straight-line distance from the northernmost part of Western Can ...
. In eastern Colorado, the highway crosses the
Great Plains
The Great Plains is a broad expanse of plain, flatland in North America. The region stretches east of the Rocky Mountains, much of it covered in prairie, steppe, and grassland. They are the western part of the Interior Plains, which include th ...
, connecting Denver with metropolitan areas in
Kansas
Kansas ( ) is a landlocked U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders Nebraska to the north; Missouri to the east; Oklahoma to the south; and Colorado to the west. Kansas is named a ...
and
Missouri
Missouri (''see #Etymology and pronunciation, pronunciation'') is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Ranking List of U.S. states and territories by area, 21st in land area, it border ...
. Bicycles and other non-motorized vehicles, normally prohibited on Interstate Highways, are allowed on those stretches of I-70 in the Rockies where no other through route exists.
The
United States Department of Transportation
The United States Department of Transportation (USDOT or DOT) is one of the executive departments of the U.S. federal government. It is headed by the secretary of transportation, who reports directly to the president of the United States a ...
(USDOT) lists the construction of I-70 among the engineering marvels undertaken in the Interstate Highway System and cites four major accomplishments: the section through the
Dakota Hogback
The Dakota Hogback is a long hogback ridge at the eastern fringe of the Rocky Mountains that extends north-south from southern Wyoming through Colorado and into northern New Mexico in the United States. The ridge is prominently visible as the firs ...
,
Eisenhower Tunnel
The Eisenhower Tunnel, officially the Eisenhower–Edwin C. Johnson Memorial Tunnel, is a dual-bore, four-lane vehicular tunnel in the western United States, approximately west of Denver, Colorado. The tunnel carries Interstate 70 (I-70) under ...
,
Vail Pass, and
Glenwood Canyon. The Eisenhower Tunnel, with a maximum elevation of and length of , is the longest mountain tunnel and highest point along the Interstate Highway System. The portion through Glenwood Canyon was completed on October 14, 1992. This was one of the final pieces of the Interstate Highway System to open to traffic and is one of the most expensive rural highways per mile built in the country. The
Colorado Department of Transportation
The Colorado Department of Transportation (CDOT, pronounced See Dot) is the principal department of the government of Colorado, Colorado state government that administers state government responsibility for Transportation in Colorado, transport ...
(CDOT) earned the 1993 Outstanding Civil Engineering Achievement Award from the
American Society of Civil Engineers
The American Society of Civil Engineers (ASCE) is a tax-exempt professional body founded in 1852 to represent members of the civil engineering profession worldwide. Headquartered in Reston, Virginia, it is the oldest national engineering soci ...
for the completion of I-70 through the canyon.
When the Interstate Highway System was in the planning stages, the western terminus of I-70 was proposed to be at Denver. The portion west of Denver was included in the plans after lobbying by Governor
Edwin C. Johnson, for whom one of the tunnels along I-70 is named. East of
Idaho Springs, I-70 was built along the corridor of
U.S. Highway 40 (US 40), one of the original transcontinental
U.S. Highways. West of Idaho Springs, I-70 was built along the route of
US 6, which was extended into Colorado during the 1930s.
Route description
Colorado River
I-70 enters Colorado from
Utah
Utah is a landlocked state in the Mountain states, Mountain West subregion of the Western United States. It is one of the Four Corners states, sharing a border with Arizona, Colorado, and New Mexico. It also borders Wyoming to the northea ...
,
concurrent with
US 6 and
US 50, on a plateau between the north rim of
Ruby Canyon of the
Colorado River
The Colorado River () is one of the principal rivers (along with the Rio Grande) in the Southwestern United States and in northern Mexico. The river, the List of longest rivers of the United States (by main stem), 5th longest in the United St ...
and the south rim of the
Book Cliffs
The Book Cliffs are a series of desert mountains and cliffs in western Colorado and eastern Utah in the Western United States. They are so named because the cliffs of Cretaceous sandstone capping many of the south-facing buttes appear simila ...
. The plateau ends just past the state line and the highway descends into the
Grand Valley, formed by the Colorado River and its tributaries.
The Grand Valley is home to several towns and small cities that form the
Grand Junction Metropolitan Statistical Area, the largest conurbation in the area regionally known as the
Western Slope. The highway directly serves the communities of
Fruita,
Grand Junction, and
Palisade
A palisade, sometimes called a stakewall or a paling, is typically a row of closely placed, high vertical standing tree trunks or wooden or iron stakes used as a fence for enclosure or as a defensive wall. Palisades can form a stockade.
Etymo ...
. Grand Junction is the largest city between
Denver
Denver ( ) is a List of municipalities in Colorado#Consolidated city and county, consolidated city and county, the List of capitals in the United States, capital and List of municipalities in Colorado, most populous city of the U.S. state of ...
and
Salt Lake City
Salt Lake City, often shortened to Salt Lake or SLC, is the capital and most populous city of the U.S. state of Utah. It is the county seat of Salt Lake County, the most populous county in the state. The city is the core of the Salt Lake Ci ...
and serves as the economic hub of the area.
The freeway passes to the north of downtown, while US 6 and US 50 retain their original routes through downtown. US 6 rejoins I-70 east of Grand Junction; US 50 departs on a course toward
Pueblo
Pueblo refers to the settlements of the Pueblo peoples, Native American tribes in the Southwestern United States, currently in New Mexico, Arizona, and Texas. The permanent communities, including some of the oldest continually occupied settlement ...
.
[
I-70 exits the valley through De Beque Canyon, a path carved by the Colorado River that separates the Book Cliffs from Battlement Mesa. The river and its ]tributaries
A tributary, or an ''affluent'', is a stream or river that flows into a larger stream ('' main stem'' or ''"parent"''), river, or a lake. A tributary does not flow directly into a sea or ocean. Tributaries, and the main stem river into which the ...
provide the course for the ascent up the Rocky Mountains
The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in great-circle distance, straight-line distance from the northernmost part of Western Can ...
. In the canyon, I-70 enters the Beavertail Mountain Tunnel, the first of several tunnel
A tunnel is an underground or undersea passageway. It is dug through surrounding soil, earth or rock, or laid under water, and is usually completely enclosed except for the two portals common at each end, though there may be access and ve ...
s built to route the freeway across the Rockies. This tunnel design features a curved side wall, unusual for tunnels in the United States, where most tunnels feature a curved roof and flat side walls. Engineers borrowed a European design to give the tunnel added strength. After the canyon winds past the Book Cliffs, the highway follows the Colorado River through a valley containing the communities of Parachute
A parachute is a device designed to slow an object's descent through an atmosphere by creating Drag (physics), drag or aerodynamic Lift (force), lift. It is primarily used to safely support people exiting aircraft at height, but also serves va ...
and Rifle
A rifle is a long gun, long-barreled firearm designed for accurate shooting and higher stopping power, with a gun barrel, barrel that has a helical or spiralling pattern of grooves (rifling) cut into the bore wall. In keeping with their focus o ...
.[
]
Glenwood Canyon
East of the city of Glenwood Springs
Glenwood Springs is a home rule municipality and the county seat of Garfield County, Colorado, United States. According to the 2020 United States census, the city has a population of 9,963. It is located at the confluence of the Roaring Fork ...
, the highway enters Glenwood Canyon. Both the federal and state departments of transportation have praised the engineering achievement required to build the freeway through the narrow gorge while preserving the natural beauty of the canyon. A section of roadway features the No Name Tunnel, Hanging Lake Tunnel, Reverse Curve Tunnel, 40 bridges and viaduct
A viaduct is a specific type of bridge that consists of a series of arches, piers or columns supporting a long elevated railway or road. Typically a viaduct connects two points of roughly equal elevation, allowing direct overpass across a wide ...
s, and miles of retaining walls.[ Through a significant portion of the canyon, the eastbound lanes extend ]cantilever
A cantilever is a rigid structural element that extends horizontally and is unsupported at one end. Typically it extends from a flat vertical surface such as a wall, to which it must be firmly attached. Like other structural elements, a cantilev ...
ed over the Colorado River and the westbound lanes are suspended on a viaduct several feet above the canyon floor. Along this run, the freeway hugs the north bank of the Colorado River, while the Central Corridor of the Union Pacific Railroad
The Union Pacific Railroad is a Railroad classes, Class I freight-hauling railroad that operates 8,300 locomotives over routes in 23 U.S. states west of Chicago and New Orleans. Union Pacific is the second largest railroad in the United Stat ...
(formerly the Denver and Rio Grande Western Railroad
The Denver and Rio Grande Western Railroad , often shortened to ''Rio Grande'', D&RG or D&RGW, formerly the Denver & Rio Grande Railroad, was an American Class I railroad company. The railroad started as a narrow-gauge line running south fr ...
) occupies the south bank.[
]
To minimize the hazards along this portion, a command center staffed with emergency response vehicles and tow truck
A tow truck (also called a wrecker, a breakdown truck, recovery vehicle or a breakdown lorry) is a truck used to move disabled, improperly parked, Vehicle impoundment, impounded, or otherwise indisposed motor vehicles. This may involve recoverin ...
s on standby monitors cameras along the tunnels and viaducts in the canyon. Traffic signals have been placed at strategic locations to stop traffic in the event of an accident, and variable message signs
A variable- (also changeable-, electronic-, or dynamic-) message sign or message board, often abbreviated VMS, VMB, CMS, or DMS, and in the UK known as a matrix sign,
is an electronic traffic sign often used on roadways to give travelers info ...
equipped with radar gun
A radar speed gun, also known as a radar gun, speed gun, or speed trap gun, is a device used to measure the speed of moving objects. It is commonly used by police to check the speed of moving vehicles while conducting Traffic police, traffic enf ...
s will automatically warn motorists exceeding the design speed of one of the curves.
Rocky Mountains
The highway departs the Colorado River near Dotsero, the name given to the railroad separation for the two primary mountain crossings, the original via Tennessee Pass/Royal Gorge
The Royal Gorge is a canyon of the Arkansas River located west of Cañon City, Colorado. The canyon begins at the mouth of Grape Creek, about west of central Cañon City, and continues in a west-northwesterly direction for approximately unti ...
and the newer and shorter Moffat Tunnel route. I-70 uses a separate route between the two rail corridors. From this junction, I-70 follows the Eagle River toward Vail Pass, at an elevation of . In this canyon, I-70 reaches the western terminus of US 24, which meanders through the Rockies before rejoining I-70. US 24 is known as the Highway of the Fourteener
In the mountaineering parlance of the Western United States, a fourteener (also spelled 14er) is a mountain peak with an elevation of at least . The 96 fourteeners in the United States are all west of the Mississippi River. Colorado
Co ...
s, from the concentration of mountains exceeding along the highway corridor. Along the ascent, I-70 serves the ski resort
A ski resort is a resort developed for skiing, snowboarding, and other winter sports. In Europe, most ski resorts are towns or villages in or adjacent to a ski area–a mountainous area with pistes (ski trails) and a ski lift system. In North Am ...
town of Vail
Vail is a home rule municipality in Eagle County, Colorado, United States. The population of the town was 4,835 in 2020. Home to Vail Ski Resort, the largest ski mountain in Colorado, the town is known for its hotels, dining, and for the nume ...
and the ski areas of Beaver Creek Resort
Beaver Creek Resort is an alpine ski resort in the western United States, near Avon, Colorado. The resort comprises three villages, the main Beaver Creek Village, Bachelor Gulch, and Arrowhead to the west. The resort is owned and operated ...
, Vail Ski Resort
Vail Ski Resort is a ski resort in the Western United States, western United States, located near the town of Vail, Colorado, Vail in Eagle County, Colorado, Eagle County, Colorado. At , it is the third-largest single-mountain ski resort in the U ...
, and Copper Mountain.[
]
The construction of the freeway over Vail Pass is also listed as an engineering marvel. One of the challenges of this portion is the management of the wildlife
Wildlife refers to domestication, undomesticated animals and uncultivated plant species which can exist in their natural habitat, but has come to include all organisms that grow or live wilderness, wild in an area without being species, introdu ...
that roams this area. Several parts of the approach to the pass feature large fences that prevent wildlife from crossing the freeway and direct the animals to one of several underpasses. At least one underpass is located along a natural migratory path and has been landscaped to encourage deer
A deer (: deer) or true deer is a hoofed ruminant ungulate of the family Cervidae (informally the deer family). Cervidae is divided into subfamilies Cervinae (which includes, among others, muntjac, elk (wapiti), red deer, and fallow deer) ...
to cross.
The highway descends to Dillon Reservoir
Dillon Reservoir, sometimes referred to as Lake Dillon, is a large fresh water reservoir located in Summit County, Colorado, United States, south of I-70 and bordered by the towns of Frisco, Silverthorne, and Dillon. It is a reservoir for th ...
, near the town of Frisco, and begins one final ascent to the Eisenhower Tunnel
The Eisenhower Tunnel, officially the Eisenhower–Edwin C. Johnson Memorial Tunnel, is a dual-bore, four-lane vehicular tunnel in the western United States, approximately west of Denver, Colorado. The tunnel carries Interstate 70 (I-70) under ...
, where the freeway crosses the Continental Divide
A continental divide is a drainage divide on a continent such that the drainage basin on one side of the divide feeds into one ocean or sea, and the basin on the other side either feeds into a different ocean or sea, or else is endorheic, not ...
. At the time of dedication, this tunnel was the highest vehicular tunnel in the world, at .[ , the facility was still the highest vehicular tunnel in the US.] The Eisenhower Tunnel is noted as both the longest mountain tunnel and the highest point on the Interstate Highway System. The tunnel has a command center, staffed with 52 full-time employees, to monitor traffic, remove stranded vehicles, and maintain generators to keep the tunnel's lighting and ventilation systems running in the event of a power failure. Signals are placed at each entrance and at various points inside the tunnel to close lanes or stop traffic in an emergency.[ There are several active and former ski resorts in the vicinity of the tunnel, including ]Breckenridge Ski Resort
Breckenridge Ski Resort is an alpine ski resort in the western United States, in Breckenridge, Colorado. Recognized for acres of skiable terrain across five mountain peaks, it welcomes thousands of skiers and snowboarders each season. Just we ...
, Keystone Resort
Keystone Resort is a ski resort located in Keystone, Colorado, United States. Since 1997, the resort has been owned and operated by Vail Resorts. It consists of three mountains (Dercum Mountain, North Peak, and the Outback) and five Bowls (I ...
, Arapahoe Basin, Loveland Ski Area
Loveland Ski Area is a ski area in the western United States, located near the town of Georgetown, Colorado. Located at the eastern portal of the Eisenhower Tunnel, Loveland is within the Arapahoe National Forest. It is one of the closest sk ...
, Berthoud Pass Ski Area, and Winter Park Resort
Winter Park Resort is an alpine ski resort in the western United States, in the Rocky Mountains of Colorado at Winter Park. Located in Grand County just off U.S. Highway 40, the resort is about a ninety-minute drive from Denver.
History
The ...
.[
]
Clear Creek
The freeway follows Clear Creek down the eastern side of the Rockies, passing through the Veterans Memorial Tunnels near Idaho Springs. Farther to the east, I-70 departs the US 6 corridor, which continues to follow Clear Creek through a narrow, curving gorge. The Interstate, however, follows the corridor of US 40 out of the canyon. The highway crests a small mountain near Genesee Park to descend into Mount Vernon Canyon to exit the Rocky Mountains.[ This portion features grade-warning signs with unusual messages, such as "Trucks: Don't be fooled", "Truckers, you are not down yet", and "Are your brakes adjusted and cool?".] Runaway truck ramp
A runaway truck ramp, runaway truck lane, escape lane, safety ramp, emergency escape ramp, or truck arrester bed is a traffic device that enables vehicles which are having braking problems to stop safely. It is typically a long, sand- or gravel- ...
s are a prominent feature along this portion of I-70,[ with a total of seven used along the descent of either side the Continental Divide to stop trucks with failed brakes.][
]
The last geographic feature of the Rocky Mountains traversed before the highway reaches the Great Plains is the Dakota Hogback
The Dakota Hogback is a long hogback ridge at the eastern fringe of the Rocky Mountains that extends north-south from southern Wyoming through Colorado and into northern New Mexico in the United States. The ridge is prominently visible as the firs ...
. The path through the hogback features a massive cut that exposes various layers of rock millions of years old. The site includes a nature study area for visitors.
Great Plains
As the freeway passes from the Rocky Mountains to the Great Plains
The Great Plains is a broad expanse of plain, flatland in North America. The region stretches east of the Rocky Mountains, much of it covered in prairie, steppe, and grassland. They are the western part of the Interior Plains, which include th ...
, I-70 enters the Denver metropolitan area
Denver is the central city of a conurbation region in the U.S. state of Colorado. The conurbation includes one continuous region consisting of the six central counties of Adams, Arapahoe, Broomfield, Denver, Douglas, and Jefferson. The Denver regi ...
, part of a larger urban area called the Front Range Urban Corridor. The freeway arcs around the northern edge of the LoDo district, the common name of the lower downtown area of Denver. Through the downtown area, US 40 is routed along Colfax Avenue
Colfax Avenue is the main street that runs east–west through the Denver metropolitan area in Colorado. As U.S. Highway 40, it was one of two principal highways serving Denver before the Interstate Highway System was constructed. In the loca ...
, which served as the primary east–west artery through the Denver area before the construction of I-70. Through downtown, US 6 is routed along 6th Avenue before departing the I-70 corridor to join I-76 on a northeast course toward Nebraska
Nebraska ( ) is a landlocked U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders South Dakota to the north; Iowa to the east and Missouri to the southeast, both across the Missouri River; Ka ...
.[ The freeway meets ]I-25
Interstate 25 (I-25), also known as the Pan-American Freeway, is a major Interstate Highway in the western United States. It is primarily a north–south highway, serving as the main route through New Mexico, Colorado, and Wyoming. I-25 st ...
in an interchange frequently called the Mousetrap
A mousetrap is a specialized type of animal trap designed primarily to catch and, usually, kill Mouse, mice. Mousetraps are usually set in an indoor location where there is a suspected infestation of rodents. Larger traps are designed to catch ...
.[ From I-25 on to I-225, I-70 serves—together with those two Interstates—as part of an inner ]beltway
A ring road (also known as circular road, beltline, beltway, circumferential (high)way, loop or orbital) is a road or a series of connected roads encircling a town, city or country. The most common purpose of a ring road is to assist in reducin ...
around Denver.
I-70 has one official branch in Colorado, I-270, which connects the Interstate with the Denver–Boulder Turnpike. Where these two freeways merge is the busiest portion of I-70 in the state, with an average
In colloquial, ordinary language, an average is a single number or value that best represents a set of data. The type of average taken as most typically representative of a list of numbers is the arithmetic mean the sum of the numbers divided by ...
of 183,000 vehicles per day . While State Highway 470 (SH 470) and E-470 are not officially branches of I-70, they are remnants of plans for an I-470 outer beltway around Denver that were canceled when the allocated funds were spent elsewhere.
Leaving Denver, the highway serves the redevelopment areas on the former site of Stapleton International Airport
Stapleton International Airport was a major airport in the western United States, and the primary airport of Denver, Colorado. It opened on October 17, 1929, and was replaced by the current Denver International Airport in 1995.
It was a hub f ...
; runway 17R/35L crossed over the Interstate at the runway's midsection.[ East of ]Aurora
An aurora ( aurorae or auroras),
also commonly known as the northern lights (aurora borealis) or southern lights (aurora australis), is a natural light display in Earth's sky, predominantly observed in high-latitude regions (around the Arc ...
, I-70 rejoins the alignment of US 40 at Colfax Avenue. The freeway proceeds east across the Great Plains, briefly dipping south to serve the city of Limon, which bills itself as Hub City because of the many rail and road arteries that intersect there. I-70 enters Kansas near Burlington, a small community known for having one of the oldest carousel
A carousel or carrousel (mainly North American English), merry-go-round (International English), or galloper (British English) is a type of amusement ride consisting of a rotating circular platform with seats for riders. The seats are tradit ...
s in the United States.
History
In 1944, a report to the United States Congress
The United States Congress is the legislature, legislative branch of the federal government of the United States. It is a Bicameralism, bicameral legislature, including a Lower house, lower body, the United States House of Representatives, ...
outlined several interregional highways, among which was a freeway from the east along the US 40 corridor that ended in Denver
Denver ( ) is a List of municipalities in Colorado#Consolidated city and county, consolidated city and county, the List of capitals in the United States, capital and List of municipalities in Colorado, most populous city of the U.S. state of ...
. After Colorado officials lobbied successfully, the designation was extended west over the Rocky Mountains following US 6.[ The origins of both the US 40 and US 6 predate the ]United States Numbered Highway System
The United States Numbered Highway System (often called U.S. Routes or U.S. Highways) is an integrated network of roads and highways numbered within a nationwide grid in the contiguous United States. As the designation and numbering of these ...
, using established transcontinental trails.
Earlier routes
Before the formation of the US Highway System, the country relied on an informal network of roads, organized by various competing interests, collectively called the auto trail
The system of auto trails was an informal network of marked routes that existed in the United States and Canada in the early part of the 20th century. Marked with colored bands on utility poles, the trails were intended to help travellers in t ...
system. The surveyors of most trails chose either South Pass in Wyoming
Wyoming ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States, Western United States. It borders Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho t ...
or a southern route through New Mexico
New Mexico is a state in the Southwestern United States, Southwestern region of the United States. It is one of the Mountain States of the southern Rocky Mountains, sharing the Four Corners region with Utah, Colorado, and Arizona. It also ...
to traverse the Rocky Mountains. Both options were less formidable than the higher mountain pass
A mountain pass is a navigable route through a mountain range or over a ridge. Since mountain ranges can present formidable barriers to travel, passes have played a key role in trade, war, and both Human migration, human and animal migration t ...
es in Colorado but left the state without a transcontinental artery. When the planners of the Lincoln Highway
The Lincoln Highway is one of the first transcontinental highways in the United States and one of the first highways designed expressly for automobiles. Conceived in 1912 by Indiana entrepreneur Carl G. Fisher, and formally dedicated Octob ...
also decided to cross the Rockies in Wyoming, officials pressed for a loop to branch from the main route in Nebraska
Nebraska ( ) is a landlocked U.S. state, state in the Midwestern United States, Midwestern region of the United States. It borders South Dakota to the north; Iowa to the east and Missouri to the southeast, both across the Missouri River; Ka ...
, enter Colorado, and return to the main route in Wyoming. When the Lincoln Highway opened in 1913, it was routed this way, but the loop proved impractical and was removed in 1915.[
]
After losing the connection to the Lincoln Highway, in 1922 officials convinced planners of the Victory Highway
The Victory Highway was an auto trail across the United States between New York City and San Francisco, roughly equivalent to the present U.S. Route 40. It was created by the Victory Highway Association, which was organized in 1921 to locate and ...
to traverse the state. The highway entered Colorado from Kansas along what was previously called the Smoky Hill Trail. The highway crossed the mountains along a trail blazed by a railroad surveyor and captain in the American Civil War
The American Civil War (April 12, 1861May 26, 1865; also known by Names of the American Civil War, other names) was a civil war in the United States between the Union (American Civil War), Union ("the North") and the Confederate States of A ...
, cresting at Berthoud Pass
Berthoud Pass ( ; elevation ) is a high mountain pass in central Colorado, in the Front Range of the Rocky Mountains of the western United States.
The pass is located west of Denver, and provides a high route between upper Clear Creek Canyon ...
.[ After a round of political infighting between Utah and Nevada, the Victory Highway would become the Lincoln Highway's main rival for ]San Francisco
San Francisco, officially the City and County of San Francisco, is a commercial, Financial District, San Francisco, financial, and Culture of San Francisco, cultural center of Northern California. With a population of 827,526 residents as of ...
-bound traffic. When the U.S. Highway system was unveiled in 1926, the Victory Highway was numbered US 40.[
While US 6 was also one of the original 1926 US Highways, the road originally served the portion of the country east of the Rocky Mountains. The highway was not extended to the ]Pacific coast
Pacific coast may be used to reference any coastline that borders the Pacific Ocean.
Geography Americas North America
Countries on the western side of North America have a Pacific coast as their western or south-western border. One of th ...
until 1937, mostly following the Midland Trail. Around the time the U.S. Highway system was formed, the portion of the Midland Trail through Glenwood Canyon, known as the Taylor State Road, was destroyed by a flood.[ When US 6 was extended, the ]Works Progress Administration
The Works Progress Administration (WPA; from 1935 to 1939, then known as the Work Projects Administration from 1939 to 1943) was an American New Deal agency that employed millions of jobseekers (mostly men who were not formally educated) to car ...
was rebuilding the road through the canyon and the Public Works Administration
The Public Works Administration (PWA), part of the New Deal of 1933, was a large-scale public works construction agency in the United States headed by United States Secretary of the Interior, Secretary of the Interior Harold L. Ickes. It was ...
was nearing completion of a new highway over Vail Pass.[ In western Colorado, US 6 was routed concurrent with US 50 from the Utah state line to Grand Junction and eventually replaced US 24 from Grand Junction to near Vail.] To keep these routes over the Rockies competitive with alternatives in other states, the Colorado Department of Highways relied on ingenuity to keep the roads safe. The department pioneered new machines to clear snow and various bridge and culvert designs to protect the roads from flooding.[
]
Interstate Highway planning
Governor Edwin C. Johnson, for whom one of the tunnels along I-70 was later named, was a primary force in persuading the planners of the Interstate Highway System
The Dwight D. Eisenhower National System of Interstate and Defense Highways, commonly known as the Interstate Highway System, or the Eisenhower Interstate System, is a network of controlled-access highways that forms part of the National Hi ...
to extend the highway across the state. He stated to the Senate subcommittee in 1955:
You are going to have a four-lane highway through Wyoming. You are going to build two four-lane highways through New Mexico and Arizona. Colorado needs to be able to compete with our neighboring states. We do not want to take anything away from them. We do not want them to get way out ahead of us, either, because these interstate highways are going to be very attractive highways for the East and West to travel on.
Colorado held several meetings to convince reluctant Utah officials they would benefit from a freeway link between Denver and Salt Lake City
Salt Lake City, often shortened to Salt Lake or SLC, is the capital and most populous city of the U.S. state of Utah. It is the county seat of Salt Lake County, the most populous county in the state. The city is the core of the Salt Lake Ci ...
. Utah officials expressed concerns that, given the terrain between these cities, this link would be difficult to build. They later expressed concerns that the construction would drain resources from completing Interstate Highways they deemed to have a higher priority. Colorado officials persisted, presenting three alternatives to route I-70 west of Denver, using the corridors of US 40, US 6, and a route starting at Pueblo
Pueblo refers to the settlements of the Pueblo peoples, Native American tribes in the Southwestern United States, currently in New Mexico, Arizona, and Texas. The permanent communities, including some of the oldest continually occupied settlement ...
, proceeding west along US 50/ US 285/US 24. In March 1955, Colorado officials succeeded in convincing Utah officials with the state legislature passing a resolution supporting a link with Denver. The two states jointly issued a proposal to Congress
A congress is a formal meeting of the representatives of different countries, constituent states, organizations, trade unions, political parties, or other groups. The term originated in Late Middle English to denote an encounter (meeting of ...
that would extend the plans for I-70 along the US 6 corridor. Under this proposal, the freeway would terminate at I-15
I15 may refer to:
* Interstate 15, a north–south Interstate Highway in the United States of America
* Polikarpov I-15, a Soviet fighter aircraft
* I15 (band), a band
* , of the Imperial Japanese Navy
* Älvsborg Regiment
The Älvsborg Regiment ...
near Spanish Fork, Utah
Spanish Fork is a city in Utah County, Utah, United States. It is part of the Provo–Orem metropolitan area. The 2020 census reported a population of 42,602. Spanish Fork is the 20th largest city in Utah based on official 2017 estimates from the ...
, linking the Front Range
The Front Range is a mountain range of the Southern Rocky Mountains of North America located in the central portion of the U.S. State of Colorado, and southeastern portion of the U.S. State of Wyoming. It is the first mountain range encounter ...
and Wasatch Front
The Wasatch Front is a major metropolitan region in the north-central part of the U.S. state of Utah. It consists of a chain of contiguous cities and towns stretched along the Wasatch Range from Santaquin in the south to Pleasant View in the n ...
metropolitan areas.[
]
Congress approved the extension of I-70; however, the route still had to be approved by the representatives of the military on the planning committee. Military representatives were concerned that plans for this new highway network did not have a direct connection from the central part of the country to Southern California
Southern California (commonly shortened to SoCal) is a geographic and Cultural area, cultural List of regions of California, region that generally comprises the southern portion of the U.S. state of California. Its densely populated coastal reg ...
; and further felt Salt Lake City was adequately connected. Military planners approved the extension but moved the western terminus south to Cove Fort, using I-70 as part of a link between Denver with Los Angeles
Los Angeles, often referred to by its initials L.A., is the List of municipalities in California, most populous city in the U.S. state of California, and the commercial, Financial District, Los Angeles, financial, and Culture of Los Angeles, ...
instead of Salt Lake City. Utah officials objected to the modification, complaining they were being asked to build a long and expensive freeway that would serve no populated areas of the state. After being told this was the only way the military would approve the extension, Utah officials agreed to build the freeway along the approved route.[
]
Construction
The first Colorado portion of I-70 opened to traffic in 1961. This section bypassed and linked Idaho Springs to the junction where US 6 currently separates from I-70 west of the city. The majority of the alignment through Denver was completed by 1964. The Mousetrap
A mousetrap is a specialized type of animal trap designed primarily to catch and, usually, kill Mouse, mice. Mousetraps are usually set in an indoor location where there is a suspected infestation of rodents. Larger traps are designed to catch ...
reused some structures that were built in 1951, before the formation of the Interstate Highway System. The last piece east of Denver opened to traffic in 1977.[
]
Eisenhower Tunnel
Planning on how to route the freeway over the Rocky Mountains began in the early 1960s. The US 6 corridor crosses two passes: Loveland Pass
Loveland Pass is a high mountain pass in north-central Colorado, at an elevation of above sea level in the Rocky Mountains of the Western United States.
Background
It is located on the Continental Divide in the Front Range, west of Denver on ...
, at an elevation of , and Vail Pass, at .[ Engineers recommended tunneling under Loveland Pass to bypass the steep grades and hairpin curves required to navigate US 6. The project was originally called the Straight Creek Tunnel, after the waterway that runs along the western approach. The tunnel was later renamed the Eisenhower–Johnson Memorial Tunnel, after President ]Dwight D. Eisenhower
Dwight David "Ike" Eisenhower (born David Dwight Eisenhower; October 14, 1890 – March 28, 1969) was the 34th president of the United States, serving from 1953 to 1961. During World War II, he was Supreme Commander of the Allied Expeditionar ...
and Colorado Governor Edwin C. Johnson.[
Construction on the first bore of the tunnel was started on March 15, 1968.][ Construction efforts suffered many setbacks, and the project went well over time and budget. One of the biggest setbacks was the discovery of ]fault lines
In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic f ...
in the path of the tunnel that were not discovered during the pilot
An aircraft pilot or aviator is a person who controls the flight of an aircraft by operating its Aircraft flight control system, directional flight controls. Some other aircrew, aircrew members, such as navigators or flight engineers, are al ...
bores.[ These faults began to slip during construction and emergency measures had to be taken to protect the tunnels and workers from cave-ins and collapses.][ A total of nine workers were killed during the construction of both bores. Further complicating construction was that the boring machines could not work as fast as expected at such high altitudes, and the productivity was significantly less than planned. The frustration prompted one engineer to comment, "We were going by the book, but the damned mountain couldn't read."] The first bore was dedicated March 8, 1973. Initially, this tunnel was used for two-way traffic, with one lane for each direction. The amount of traffic through the tunnel exceeded predictions, and efforts soon began to expedite construction on the second tube (the Johnson bore), which was finished on December 21, 1979.[ The initial engineering cost estimate for the Eisenhower bore was $42 million; the actual cost was $108 million (equivalent to $ in ). Approximately 90 percent of the funds were paid by the federal government, with the state of Colorado paying the rest. At the time, this figure set a record for the most expensive federally aided project. The excavation cost for the Johnson bore was $102.8 million (equivalent to $ in ).]
The tunnel construction became involved in the women's rights movement
Women's rights are the rights and Entitlement (fair division), entitlements claimed for women and girls worldwide. They formed the basis for the women's rights movement in the 19th century and the feminist movements during the 20th and 21st c ...
due to advocacy by Janet Bonnema after she was subjected to gender-based discrimination after being hired as an engineering technician for the construction of the Straight Creek Tunnel in 1970. Bonnema was restricted from entering the tunnel due to the miners' superstition that women who entered underground mines and tunnels would bring bad luck. In 1972, Bonnema filed a $100,000 class action suit against CDOT, citing Title VII of the Civil Rights Act of 1964
The Civil Rights Act of 1964 () is a landmark civil rights and United States labor law, labor law in the United States that outlaws discrimination based on Race (human categorization), race, Person of color, color, religion, sex, and nationa ...
. As Colorado voters had passed the Equal Rights Amendment
The Equal Rights Amendment (ERA) was a proposed amendment to the Constitution of the United States, United States Constitution that would explicitly prohibit sex discrimination. It is not currently a part of the Constitution, though its Ratifi ...
that year, the state settled Bonnema's case out of court for $6,730. Bonnema entered the tunnel for the first time on November 9, 1972, prompting 66 workers to temporarily walk off the job; most returned the next day. She continued with the project until the tunnel opened.
Vail Pass
While designing the Eisenhower Tunnel, controversies erupted over how to build the portions over Vail Pass and Glenwood Canyon. The route of US 6 over Vail Pass has a distinctive "V" shape. Initially, engineers thought they could shorten the route of I-70 by about by tunneling from Gore Creek to South Willow Creek, an alternative known as the Red Buffalo Tunnel.[ This alternative sparked a nationwide controversy as it would require an ]easement
An easement is a Nonpossessory interest in land, nonpossessory right to use or enter onto the real property of another without possessing it. It is "best typified in the right of way which one landowner, A, may enjoy over the land of another, B" ...
across federally protected lands, through what is now called the Eagles Nest Wilderness. After the US Secretary of Agriculture refused to grant the easement, the engineers agreed to follow the existing route across Vail Pass. The engineers added infrastructure to accommodate wildlife and had significant portions of the viaducts constructed offsite and lifted in place to minimize the environmental footprint.[ The grade over Vail Pass reaches seven percent.
]
Glenwood Canyon
Glenwood Canyon has served as the primary transportation artery through the Rocky Mountains, even before the creation of U.S. Highways. Railroads have used the canyon since 1887, and a dirt road was built through the canyon in the early 20th century.[ The first paved road was built from 1936 to 1938 at a cost of $1.5 million (equivalent to $ in ).][
With the Eisenhower Tunnel finished, the last remaining obstacle for I-70 to be an interstate commercial artery was the two lane, non-freeway portion in Glenwood Canyon. Construction had started on this section in the 1960s with a small section opening to traffic in 1966.][ The remainder was stopped due to ]environmentalist
Environmentalism is a broad Philosophy of life, philosophy, ideology, and social movement about supporting life, habitats, and surroundings. While environmentalism focuses more on the environmental and nature-related aspects of Green politics, g ...
protests that caused a 30-year controversy.[ The original design was criticized as "the epitome of environmental insensitivity". Engineers scrapped the original plans and started work on a new design that would minimize additional environmental impacts.] A new design was underway by 1971, which was approved in 1975; however, environmental groups filed lawsuits to stop construction, and the controversy continued even when construction finally resumed in 1981.[ The final design included 40 bridges and viaducts, three additional tunnel bores (two were completed before construction was stopped in the 1960s), and of retaining walls for a stretch of freeway long.][ The project was further complicated by the need to build the four-lane freeway without disturbing the operations of the railroad. This required using special and coordinated blasting techniques.] Engineers designed two separate tracks for the highway, one elevated above the other, to minimize the footprint in the canyon.[ The final design was praised for its environmental sensitivity. A Denver architect who helped design the freeway proclaimed, "Most of the people in western Colorado see it as having preserved the canyon." He further stated, "I think pieces of the highway elevate to the standard of public art."][ A portion of the project included shoring up the banks of the Colorado River to repair damage and remove flow restrictions created in the initial construction of US 6 in the 1930s.]
The freeway was finally completed on October 14, 1992, in a ceremony covered nationwide. Most coverage celebrated the engineering achievement or noted this was the last major piece of the Interstate Highway System to open to traffic. However, newspapers in western Colorado celebrated the end of the frustrating traffic delays. For most of the final 10 years of construction, only a single lane of traffic that reversed direction every 30 minutes remained open in the canyon. One newspaper proudly proclaimed "You heard right. For the first time in more than 10 years, construction delays along that stretch of Interstate 70 will be non-existent."
The cost was $490 million (equivalent to $ in ) to build , 40 times the average cost per mile predicted by the planners of the Interstate Highway System.[ This figure exceeded that of ]I-15
I15 may refer to:
* Interstate 15, a north–south Interstate Highway in the United States of America
* Polikarpov I-15, a Soviet fighter aircraft
* I15 (band), a band
* , of the Imperial Japanese Navy
* Älvsborg Regiment
The Älvsborg Regiment ...
through the Virgin River Gorge, which was previously proclaimed the most expensive rural freeway in the country. The construction of I-70 through Glenwood Canyon earned 30 awards for CDOT,[ including the 1993 Outstanding Civil Engineering Achievement Award from the ]American Society of Civil Engineers
The American Society of Civil Engineers (ASCE) is a tax-exempt professional body founded in 1852 to represent members of the civil engineering profession worldwide. Headquartered in Reston, Virginia, it is the oldest national engineering soci ...
. At the dedication, it was claimed that I-70 through Glenwood Canyon was the final piece of the Interstate Highway System to open to traffic. For this reason, the system was proclaimed to be complete.[ However, at the time, there were still two sections of the original Interstate Highway System that had not been constructed: a section of ]I-95
Interstate 95 (I-95) is the main north–south Interstate Highway on the East Coast of the United States, running from U.S. Route 1 (US 1) in Miami, Florida, north to the Houlton–Woodstock Border Crossing between Maine and the ...
in central New Jersey
Central Jersey, or Central New Jersey, is the middle region of the U.S. state of New Jersey. The designation Central Jersey is a distinct administrative division, administrative toponymy, toponym. While New Jersey is often divided into North Je ...
, that was not completed until 2018, and a section of I-70 in Breezewood, Pennsylvania.
Realignments
In 2022, CDOT replaced a viaduct that formerly carried I-70 between Brighton Boulevard and Colorado Boulevard in Denver with a below-grade highway. The $1.2 billion project, financed through a public–private partnership
A public–private partnership (PPP, 3P, or P3) is a long-term arrangement between a government and private sectors, private sector institutions.Hodge, G. A and Greve, C. (2007), Public–Private Partnerships: An International Performance Revie ...
with Kiewit
Kiewit () is a Belgium, Belgian parish and village within the northernmost extension of the Flemish region, Flemish municipality of Hasselt. It also borders on the municipality of Zonhoven to the north and Genk to the east, with Kuringen, another ...
and Meridiam, added new express toll lanes; the below-grade freeway was covered with a park between Clayton and Columbine streets. Traffic was moved onto the new alignment in late 2022; however, the project was not fully complete until July 2023.
Incidents
On August 1, 1984, a truck carrying six torpedo
A modern torpedo is an underwater ranged weapon launched above or below the water surface, self-propelled towards a target, with an explosive warhead designed to detonate either on contact with or in proximity to the target. Historically, such ...
es for the US Navy
The United States Navy (USN) is the naval warfare, maritime military branch, service branch of the United States Department of Defense. It is the world's most powerful navy with the largest Displacement (ship), displacement, at 4.5 millio ...
overturned while navigating a ramp at the Mousetrap
A mousetrap is a specialized type of animal trap designed primarily to catch and, usually, kill Mouse, mice. Mousetraps are usually set in an indoor location where there is a suspected infestation of rodents. Larger traps are designed to catch ...
, a complex interchange. The situation was made worse as no one answered at the phone number provided with the cargo, and an unknown liquid was leaking from one of the torpedoes. It took more than three hours before any military personnel arrived on the scene, US Army
The United States Army (USA) is the primary land service branch of the United States Department of Defense. It is designated as the Army of the United States in the United States Constitution.Article II, section 2, clause 1 of the United Stat ...
personnel from a nearby base. The incident left thousands of cars stranded and Denver's transportation network paralyzed for about eight hours. Approximately 50 residents in the area were evacuated. Investigations later revealed that the truck driver was previously intercepted by the Colorado State Patrol
The Colorado State Patrol (CSP) (originally known as the Colorado State Highway Courtesy Patrol), based in Lakewood, Colorado, is a division of the Colorado Department of Public Safety, and is one of the official state police agencies of Colorado ...
, who specifically warned the driver to avoid the Mousetrap and provided the driver with an alternate route.[ The Navy promised reforms after being criticized for providing an unstaffed phone number with a hazardous cargo shipment, a violation of federal law, and failing to notify Denver officials about the shipment.] The Mousetrap was grandfathered into the Interstate Highway System, with some structures built in 1951.[ The incident provided momentum to rebuild the interchange with a more modern and safer design. Construction began in several phases in 1987, and the last bridge was dedicated in 2003.]
In 2014, mile-marker 420 was altered by CDOT to read "Mile 419.99" following repeat thefts of the original sign due to the significance of the number 420 in cannabis culture.
In 2019, a fiery crash killed four people and injured dozens. A previous, non-fatal accident in Wheat Ridge had resulted in backed up traffic for several miles. At the time of the second collision, the backup extended into Lakewood past the Colorado Mills Parkway exit. A semi-trailer truck
A semi-trailer truck (also known by a wide variety of other terms – see below) is the combination of a tractor unit and one or more semi-trailers to carry freight. A semi-trailer attaches to the tractor with a type of hitch called ...
descending the grades as the freeway entered the greater Denver area, driven by Rogel Aguilera Mederos, attempted to downshift, but he was unable re-engage the transmission.[ This resulted in the vehicle rapidly increasing in speed, with witnesses seeing the truck out of control near the Genesee exit, from where the accident would occur. Witnesses also testified seeing the brakes smoking while the truck descended the hill. The driver passed at least one ]runaway truck ramp
A runaway truck ramp, runaway truck lane, escape lane, safety ramp, emergency escape ramp, or truck arrester bed is a traffic device that enables vehicles which are having braking problems to stop safely. It is typically a long, sand- or gravel- ...
without entering, as well as four other exits where he could have exited the freeway. As the truck approached the backed up traffic, the driver attempted to swerve to the side of the road to avoid a collision but was unable as other trucks had already blocked this path while similarly attempting to avoid a collision. The truck collided with the backup and exploded. Over a dozen other vehicles were involved in the collision and four people died. The driver was charged with numerous offenses, including assault and vehicular homicide and initially sentenced to 110 years. This was controversial, due to the length of the sentence and the opinions of some victims and witnesses that the owner of the truck bore more responsibility. The company had previously been fined and cited for numerous brake-related violations as well as employing inexperienced truck drivers who were not fluent in English. Aguilera testified through an interpreter in his own defense and pleaded for mercy saying, "I ask God too many times why them and not me? Why did I survive that accident?". He also blamed his employer, testifying he was instructed to take back roads from the trip's origin in Wyoming
Wyoming ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States, Western United States. It borders Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho t ...
and avoid the more commonly used road from Wyoming, I-25
Interstate 25 (I-25), also known as the Pan-American Freeway, is a major Interstate Highway in the western United States. It is primarily a north–south highway, serving as the main route through New Mexico, Colorado, and Wyoming. I-25 st ...
. Shortly after the accident, CDOT announced a location for an additional runaway truck ramp in this area.
After the 2020 Grizzly Creek Fire, I-70 was closed in Glenwood Canyon in August 2021 due to significant damage by debris from the fire, causing large detours. The damage after the 2021 landslides required lengthy reconstruction of the road; the highway partially reopened on August 14, 2021.
Legacy
When first approved, the extension of I-70 from Denver to Cove Fort was criticized in some area newspapers as a road to nowhere; an information liaison specialist with USDOT in Baltimore, Maryland
Baltimore is the List of municipalities in Maryland, most populous city in the U.S. state of Maryland. With a population of 585,708 at the 2020 United States census, 2020 census and estimated at 568,271 in 2024, it is the List of United States ...
—the eastern terminus of I-70—claims people have asked "did we think Baltimoreans were so desperate to get to Cove Fort that we were willing to pay $4 billion to get them there?".[ However, a resident engineer with USDOT has called the extension one of the "crown jewels" of the Interstate Highway System.][ In Colorado, the freeway helped unite the state, despite the two halves being separated by the formidable Rocky Mountains. The Eisenhower Tunnel alone is credited with saving up to an hour from the drive across the state.][ Prior to I-70's construction, the highway through Glenwood Canyon was one of the most dangerous in the state. With the improvements, the accident rate has dropped 40 percent even though traffic through the canyon has substantially increased.][ CDOT is considering the nomination of various portions of I-70 as a ]National Historic Landmark
A National Historic Landmark (NHL) is a National Register of Historic Places property types, building, district, object, site, or structure that is officially recognized by the Federal government of the United States, United States government f ...
, even though the freeway will not qualify as historical for several decades.[
The freeway is credited with enhancing Colorado's ski industry. The ski resort town of ]Vail
Vail is a home rule municipality in Eagle County, Colorado, United States. The population of the town was 4,835 in 2020. Home to Vail Ski Resort, the largest ski mountain in Colorado, the town is known for its hotels, dining, and for the nume ...
did not exist until I-70 began construction, with developers working in close partnership with CDOT.[ By 1984, the I-70 corridor between Denver and Grand Junction contained the largest concentration of ski resorts in the country. The towns and cities along the corridor have experienced significant growth, luring recreational visitors from the Denver area. As one conservationist lamented, I-70 "changed rural Colorado into non-rural Colorado".][
]
Exit list
See also
* Business routes of Interstate 70 in Colorado
References
External links
I-70 Road conditions, construction updates, traffic cameras, and traveler alerts
by Colorado Department of Transportation
by AARoads
by Matthew E. Salek
by Dale Sanderson
{{DEFAULTSORT:Interstate 70 In Colorado
Colorado
70
Colorado River
Transportation in Mesa County, Colorado
Transportation in Garfield County, Colorado
Transportation in Eagle County, Colorado
Transportation in Summit County, Colorado
Transportation in Clear Creek County, Colorado
Transportation in Jefferson County, Colorado
Transportation in Denver
Transportation in Adams County, Colorado
Transportation in Arapahoe County, Colorado
Transportation in Elbert County, Colorado
Transportation in Lincoln County, Colorado
Transportation in Kit Carson County, Colorado