The Intermontane Plateaus of the Western United States is one of eight U.S. Physiographic regions (divisions) of the physical geography of the contiguous United States. The region is composed of intermontane plateaus and mountain ranges. It is subdivided into physiographic provinces, which are each subdivided into physiographic sections.
The Trigo Mountains are a north-south trending mountain range in La Paz County, Arizona, bordering the Colorado River on the east in the Lower Colorado River Valley. The range lies north of the Colorado River as it turns east, north of Martinez Lake and the Imperial Reservoir. The Trigo Mountains are on a north-south stretch of the Colorado River, and form the eastern perimeter of the Imperial National Wildlife Refuge.
The Tinajas Altas Mountains are an extremely arid northwest-southeast trending mountain range in southern Yuma County, Arizona, approximately 35 mi southeast of Yuma, Arizona. The southern end of the range extends approximately one mile into the northwestern Mexican state of Sonora on the northern perimeter of the Gran Desierto de Altar. The range is about 22 mi in length and about 4 mi wide at its widest point. The highpoint of the range is unnamed and is 2,766 feet above sea level and is located at 32°16'26"N, 114°02'48"W. Aside from the portion of the range in Mexico, the entirety of the range lies within the Barry M. Goldwater Air Force Range. They lie at the heart of the traditional homeland of the Hia C-eḍ O'odham people.
The Muggins Mountains is a mountain range in southwest Arizona east of Yuma, Arizona, northeast of the Gila Mountains, and east of the Laguna Mountains. The Castle Dome Mountains lie to the northeast across the broad Castle Dome Plain. The Muggins Mountains Wilderness occupies the southwest portion of the range.
The Bryan Mountains are a small mountain range in the northwestern Sonoran Desert of southwestern Arizona. The range is located in southeastern Yuma County, about 75 mi southeast of Yuma and about 35 mi west of Ajo. The range is approximately ten miles long and about three miles wide at its widest point. The highpoint of the range is 1,794 feet above sea level and is located at 32°18'27"N, 113°22'46"W. The range is located entirely within the Cabeza Prieta National Wildlife Refuge.
The Mohawk Mountains is a mountain range in the northwest Sonoran Desert of southwest Arizona. It abuts the western Gila River valley to the north, and is located in southern Yuma County. The Mohawk Valley lies adjacent and southwest of the range; the San Cristobal Valley is northeast.
The Gila Mountains of Yuma County are a 26-mile (42 km) long mountain range in southwestern Arizona in the northwest Sonoran Desert.
The San Cristobal Wash is an ephemeral wash and watercourse of the San Cristobal Valley, flowing north into the Gila River Valley of the southwestern desert region of Arizona. Besides Death Valley, the Chihuahuan Desert area, and regions of Baja Peninsula North America, the southeast California deserts along the Lower Colorado River Valley, this drainage region is in the harshest desert regions of North America.
Tenmile Wash is an ephemeral wash and watercourse about 85 miles (137 km) long in the northern Sonoran Desert of south-central Arizona. It forms the eastern drainage of a two drainage system of dry washes into the Gila River Valley; both flow northwesterly, and the western drainage is the San Cristobal Wash Drainage of approximately the same length.
The Riverside Mountains are a mountain range in Riverside County, California. The town of Vidal, California is located in the West Riverside Mountains.
Aubrey Cliffs are a series of cliff escarpments located in Coconino County, in northwestern Arizona.
The Altar Valley is a 45-mile (72 km) long north-south valley, trending slightly northeast from Sasabe, Arizona on the Mexico border to the Avra Valley west of the Tucson Mountains. It is delimited by Arizona State Route 86, from east-to-west on the north separating it from the Avra Valley which then trends northwesterly, merging into the plains and drainage of the Santa Cruz River.
The Granite Wash Mountains are a short, arid, low elevation mountain range of western-central Arizona, in the southeast of La Paz County. The range borders a slightly larger range southeast, the Little Harquahala Mountains; both ranges form a section on the same water divide between two desert washes. The washes flow in opposite directions, one northwest to the Colorado River, the other southeast to the Gila River.
Vidal Valley is a 20-mile (32 km) long valley in the far eastern Colorado Desert bordering the Colorado River. Most of the valley is in eastern San Bernardino County, California, but the outfall on the Colorado River is in northeast Riverside County. Vidal Valley forms the large border of the south side of the east-west block of the Whipple Mountains massif, the landform that forces the Colorado to flow southeast, then back southwest. The southeast exit of the valley into Parker Valley on the Colorado River skirts the north end of the Riverside Mountains. The Colorado River Aqueduct crosses the midpoint of the valley at Vidal Junction, California. The Vidal Valley also lies due east of the Danby Dry Lake landform.
The Belmont Mountains are a 25 mi (40 km) long, arid, low elevation mountain range about 50 mi west of Phoenix, Arizona in the northern Sonoran Desert, north of the Gila River. The range is in the south of a region of two parallel washes; the Bouse Wash flows northwest to the Colorado River, and the Centennial Wash flows southeast to meet the Gila River.
The Poachie Range is a moderate length mountain range and massif in southeast Mohave County, Arizona, and the extreme southwest corner of Yavapai County; the range also abuts the northeast corner of La Paz County. The Poachie Range massif is bordered by the south-flowing Big Sandy River on its west, and the west-flowing Santa Maria River on its south; both rivers converge at the Poachie Range's southwest at Alamo Lake, the Alamo Lake State Park.
The Aquarius Mountains are a 45-mi (72 km) long mountain range in southeast Mohave County, Arizona. The range lies in the northwest of the Arizona transition zone, and at the southwest of the Coconino Plateau, a subsection of the Colorado Plateau.
The Toroweap Fault of northwest Arizona and southwest Utah is part of a fault system of the west Grand Canyon region, Arizona, USA; also the west perimeter regions of the Coconino and Colorado Plateaus. The Hurricane Fault originates at the Toroweap Fault, in the region of the Colorado River, and strikes as the westerly expression of the Toroweap Fault. The Toroweap strikes northerly from the Colorado at the east of Toroweap Valley, and enters south Utah; from the Colorado River, the Hurricane Fault strikes north-northwest along the west flank of the small, regional Uinkaret Mountains, the west border of Toroweap Valley. The Hurricane Fault, and the Hurricane Cliffs strike into southwest Utah as part of the west, and southwest perimeter of the Colorado Plateau. The Hurricane Cliffs are made of Kaibab Limestone, an erosion resistant, cliff-forming rock unit.
The Peacock Mountains are a small, 26-mi (42 km) long mountain range in northwest Arizona, USA. The range is a narrow sub-range, and an extension north, at the northeast of the Hualapai Mountains massif, which lies to the southwest. The range is defined by the Hualapai Valley to the northwest, and north and south-flowing washes on its east border, associated with faults and cliffs; the Cottonwood Cliffs are due east, and are connected to the Aquarius Cliffs southward at the west perimeter of the Aquarius Mountains; the cliffs are a result of the Aquarius Fault, which is an extension southward from the Grand Wash Cliffs and Grand Wash Fault which crosses the Colorado River at Lake Mead, and the west perimeter of the Grand Canyon/Colorado Plateau.
