Jefferson Peak is a mountain

summit A summit is a point on a surface that is higher in elevation than all points immediately adjacent to it. The topographic terms acme, apex, peak (mountain peak), and zenith are synonymous. The term (mountain top) is generally used only for ...

located in the

Olympic Mountains The Olympic Mountains are a mountain range on the Olympic Peninsula of the Pacific Northwest of the United States. The mountains, part of the Pacific Coast Ranges, are not especially high – Mount Olympus (Washington), Mount Olympus is the high ...

in Mason County of

Washington Washington most commonly refers to: * George Washington (1732–1799), the first president of the United States * Washington (state), a state in the Pacific Northwest of the United States * Washington, D.C., the capital of the United States ** A ...

state. It is situated in the Mount Skokomish Wilderness, on land managed by

Olympic National Forest Olympic National Forest is a U.S. National Forest located in Washington. With an area of , it nearly surrounds Olympic National Park and the Olympic Mountain range. Olympic National Forest contains parts of Clallam, Grays Harbor, Jefferson, ...

. The mountain's toponym honors

Thomas Jefferson Thomas Jefferson (, 1743July 4, 1826) was an American Founding Fathers of the United States, Founding Father and the third president of the United States from 1801 to 1809. He was the primary author of the United States Declaration of Indepe ...

(1743–1826), the third president of the United States.Kai Huschke (2003), ''Washington's Wilderness Areas'', Westcliffe Publishers, , page 48. The nearest higher neighbor is

line parent A peak's line parent is the closest higher peak on the highest ridge leading away from the peak's "key col". A col is the lowest point on the ridge between two summits and is roughly synonymous with pass, gap, saddle and notch. The highest col ...

Mount Pershing, to the southwest. Precipitation runoff drains into Jefferson Creek and the Hamma Hamma River.

Topographic relief Terrain (), alternatively relief or topographical relief, is the dimension and shape of a given surface of land. In physical geography, terrain is the lay of the land. This is usually expressed in terms of the elevation, slope, and orientati ...

is significant as the north aspect rises over above the Hamma Hamma valley in approximately one mile.

Climbing

The

first ascent In mountaineering and climbing, a first ascent (abbreviated to FA in climbing guidebook, guide books), is the first successful documented climb to the top of a mountain or the top of a particular climbing route. Early 20th-century mountaineers a ...

of the summit was made in 1958 by Don Anderson, Bob Oram, Keith Spencer, and Robert Petersen. There are three established scrambling routes to the summit: from Goober Pond, the North Couloir, and via the East Peak. Jefferson Peak has a 250-foot-high () subpeak called "Tran Spire" () which was first climbed in 1958 by Don Anderson and Robert Petersen .

Climate

Jefferson Peak is located in the

marine west coast An oceanic climate, also known as a marine climate or maritime climate, is the temperate climate sub-type in Köppen classification represented as ''Cfb'', typical of west coasts in higher middle latitudes of continents, generally featuring co ...

climate zone of western

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

Weather front A weather front is a boundary separating air masses for which several characteristics differ, such as air density, wind, temperature, and humidity. Disturbed and unstable weather due to these differences often arises along the boundary. For ins ...

s originating in the Pacific Ocean travel northeast toward the Olympic Mountains. As fronts approach, they are forced upward by the peaks (

orographic lift Orographic lift occurs when an air mass is forced from a low elevation to a higher elevation as it moves over rising terrain. As the air mass gains altitude it quickly cools down adiabatically, which can raise the relative humidity to 100% and cr ...

), causing them to drop their moisture in the form of rain or snow. As a result, the Olympics experience high precipitation, especially during the winter months in the form of snowfall. Because of maritime influence, snow tends to be wet and heavy, resulting in

avalanche An avalanche is a rapid flow of snow down a Grade (slope), slope, such as a hill or mountain. Avalanches can be triggered spontaneously, by factors such as increased precipitation or snowpack weakening, or by external means such as humans, othe ...

danger. During winter months weather is usually cloudy, but due to high pressure systems over the Pacific Ocean that intensify during summer months, there is often little or no cloud cover during the summer. The months April through August offer the most favorable weather for viewing or climbing this mountain.

Geology

The Olympic Mountains are composed of obducted

clastic Clastic rocks are composed of fragments, or clasts, of pre-existing minerals and rock. A clast is a fragment of geological detritus,Essentials of Geology, 3rd Ed, Stephen Marshak, p. G-3 chunks, and smaller grains of rock broken off other rocks by ...

wedge material and oceanic crust, primarily

Eocene The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes ...

sandstone Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...

turbidite A turbidite is the geologic Deposition (geology), deposit of a turbidity current, which is a type of amalgamation of fluidal and sediment gravity flow responsible for distributing vast amounts of clastic sediment into the deep ocean. Sequencing ...

, and

basalt Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...

ic oceanic crust. The mountains were sculpted during the

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

era by erosion and glaciers advancing and retreating multiple times.

Gallery

File:Jefferson mtn.jpg, Jefferson Peak centered.
(Mount Bretherton and Mount Constance to left, The Brothers to right) File:Ferry on Puget Sound.jpg, Ferry on Puget Sound. Left to right: Mt. Pershing, Jefferson Peak, Mt. Cruiser, Mt. Skokomish, Mt. Stone File:Olympics above low clouds.jpg, Left to rightː Mt. Ellinor, Mt. Washington, Mt. Pershing, Jefferson Peak.
View from Seattle. File:Olympic range mtn.jpg, Jefferson Peak

References

External links

* Weather forecast
Jefferson Peak

Mount Skokomish Wilderness
U.S. Forest Service {{Geographic Location 2 , Center = Jefferson Peak , North = Mount Bretherton , Northeast = The Brothers , East = Jefferson Lake , Southeast = Jefferson Creek , South =

Mount Washington Mount Washington is an ultra-prominent mountain in the state of New Hampshire. It is the highest peak in the Northeastern United States at and the most topographically prominent mountain east of the Mississippi River. The mountain is notorio ...