The Gila Mountains of Yuma County are a 26-mile (42 km) long mountain range in southwestern

Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...

in the northwest

Sonoran Desert The Sonoran Desert ( es, Desierto de Sonora) is a desert in North America and ecoregion that covers the northwestern Mexican states of Sonora, Baja California, and Baja California Sur, as well as part of the southwestern United States (in Ariz ...

. The Gila Mountains of Yuma County are a northwest-southeast trending mountain system. The

fault-block Fault blocks are very large blocks of rock, sometimes hundreds of kilometres in extent, created by tectonic and localized stresses in Earth's crust. Large areas of bedrock are broken up into blocks by faults. Blocks are characterized by relat ...

ed mountain range is attached on the south to the Tinajas Altas Mountains which continue southeast into Sonora, Mexico for another 30 miles. The northwest end of the mountains border the southeast

Laguna Mountains The Laguna Mountains are a mountain range of the Peninsular Ranges System in eastern San Diego County, southern California. The mountains run in a northwest/southeast alignment for approximately . The mountains have long been inhabited by the i ...

. The Gila River flows through the Gila Valley between the Gilas and the Lagunas prior to its confluence with the

Colorado Colorado (, other variants) is a state in the Mountain states, Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the wes ...

. The Gila Mountains are southeast of the confluence of the Colorado and Gila rivers in the Lower Colorado River Valley. The Gila River flows northwest, north around the mountain's north end, then west six miles to the Colorado. On the northeast side of the Gila Range, the low-elevation basin, Dome Valley is created between the

Muggins Mountains The Muggins Mountains is a mountain range in southwest Arizona east of Yuma, Arizona, Yuma, Arizona, northeast of the Gila Mountains (Yuma County), Gila Mountains, and east of the Laguna Mountains (Arizona), Laguna Mountains. The Castle Dome Mo ...

and the

Muggins Mountains Wilderness The Muggins Mountain Wilderness is a wilderness area in the U.S. state of Arizona. It is located approximately east of Yuma, Arizona in the Muggins Mountains and adjacent to the agricultural ''Dome Valley'' and Gila River. The wilderness area ...

to the northeast. The block faulted mountain series ends at this confluence location and the

are at the southern and southwest end of an extensive plain that transitions north towards the

Castle Dome Plain A castle is a type of fortified structure built during the Middle Ages predominantly by the nobility or royalty and by military orders. Scholars debate the scope of the word ''castle'', but usually consider it to be the private fortified r ...

and

Castle Dome Mountains The Castle Dome Mountains (Tolkepaya Yavapai: Wi:hopuʼ) are a mountain range in Yuma County, Arizona, within the Kofa National Wildlife Refuge. Castle Dome Peak, the high point of the range, is a prominent butte and distinctive landmark. The p ...

. This plain is the location of the

US Army The United States Army (USA) is the land service branch of the United States Armed Forces. It is one of the eight U.S. uniformed services, and is designated as the Army of the United States in the U.S. Constitution.Article II, section 2, cla ...

Yuma Proving Ground Yuma Proving Ground (YPG) is a United States Army series of environmentally specific test centers with its Yuma Test Center being one of the largest military installations in the world. It is subordinate to the U.S. Army Test and Evaluation ...

on this east-west alluvial plain. The highest peak in the arid and rugged Gila Mountains is Sheep Peak at . The mountain range lies east of Yuma and the community of

Fortuna Foothills Fortuna Foothills is a census-designated place (CDP) in Yuma County, Arizona, United States. The population was 26,265 at the 2010 census. It is part of the Yuma Metropolitan Statistical Area. Development of the area began in the 1960s, when lo ...

lies on the northwest mountain range foothills, (named for the ''Fortuna Mine''). The mountain range is located in the western portion of the Barry M. Goldwater Air Force Range which is used by the MCAS, the Marine Corps Air Station, Yuma.

Ecology

A variety of flora and fauna are represented in the Gila Mountains. Trees include '' Dalea spinosa'' and ''

Bursera microphylla ''Bursera microphylla'', known by the common name elephant tree in English or 'torote' in Spanish, is a tree in genus ''Bursera''. It grows into a distinctive sculptural form, with a thickened, water-storing or caudiciform trunk. It is found in ...

''.C. Michael Hogan. 2009

Interstate 8

One of the oldest sections of the

Interstate Highway System The Dwight D. Eisenhower National System of Interstate and Defense Highways, commonly known as the Interstate Highway System, is a network of controlled-access highways that forms part of the National Highway System in the United States. T ...

in the US goes through a two-tiered highway section through '' Telegraph Pass'' at the north end of the range. The Interstate 8 roadcuts in the area of Telegraph Pass expose some of the oldest

metamorphic rocks Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock (protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, caus ...

in the state of Arizona, outside of rocks exposed at the bottom of the Grand Canyon.

Mountain acquisition controversy

A recent controversy involves acquisition of parts of the Gila Mountains by the city of Yuma, Arizona. The controversy is protection versus land use by agencies. The mountains are presently in the Barry M. Goldwater Air Force Range.

Notes

References

* Arizona Road & Recreation Atlas, Benchmark Maps, 2nd Edition, c. 1998, 112 pages, pp. 44–45, 78-79. * Arizona DeLorme Atlas & Gazetteer, 5th Edition, c. 2002, 76 pages, p. 62. * C. Michael Hogan. 2009
''Elephant Tree: Bursera microphylla'', GlobalTwitcher.com, ed. N. Stromberg
* Charles Sprague Sargent. 1885. ''The woods of the United States'', page 26, American Museum of Natural History, 203 pages {{Mountains of Arizona Mountain ranges of the Sonoran Desert Mountain ranges of the Lower Colorado River Valley Mountain ranges of Yuma County, Arizona Mountain ranges of Arizona

Ecology

Interstate 8

Mountain acquisition controversy

See also

Notes

References