Amargosa River

The Amargosa River is a waterway, 185 miles (298 km) long, in southern Nevada and eastern California in the United States. The Amargosa River is one out of two rivers located in the California portion of the Mojave Desert with perennial flow. It drains a high desert region, the Amargosa Valley in the Amargosa Desert northwest of Las Vegas, into the Mojave Desert, and finally into Death Valley where it disappears into the ground aquifer. Except for a small portion of its route in the Amargosa Canyon in California and a small portion at Beatty, Nevada, the river flows above ground only after a rare rainstorm washes the region. A 26-mile (42 km) stretch of the river between Shoshone and Dumont Dunes is protected as a National Wild and Scenic River. At the south end of Tecopa Valley the Amargosa River Natural Area protects the habitat.

Course

Except during flash floods that occur after cloudbursts, most of the course of the Amargosa River is dry on the surface. The flow is generally underground except for stretches near Beatty and near Tecopa, California, in the Amargosa Canyon. In the canyon, the river passes through the Amargosa River Natural Area, a region of dense greenery and prolific wildlife made possible by the presence of water.

The river arises at about above sea level in Nye County, Nevada, along the southern side of Pahute Mesa in the Nellis Air Force Range. Thirsty Canyon Wash enters at the river's source, and when carrying water, the river flows from there southwest into Oasis Valley. Running parallel to U.S. Route 95 near the Bullfrog Hills to the west (right bank), the river receives Sober-Up Gulch from the right and then Beatty Wash from the left bank.

Running roughly parallel to California Route 127, the river passes through Death Valley Junction. Shortly after, it receives Carson Slough, which drains Ash Meadows National Wildlife Refuge, from the left. Soon the river passes between the Resting Spring Range to the left and the Greenwater Range to the right before reaching Shoshone. Below Shoshone, the river continues roughly parallel to Route 127 to Tecopa. Downstream of Tecopa, with the Old Spanish Trail, it passes through the Amargosa Canyon between the Sperry Hills on the right and the Dumont Hills on the left, enters San Bernardino County, California, and flows by Dumont Dunes in the northern Mojave Desert. Turning west, the river crosses under Route 127 and enters Death Valley National Park between the south end of the Amargosa Range on the right and the Avawatz Mountains on the left. that is the remnant of prehistoric Lake Manly.

Discharge

thumb|Stream running into Amargosa River.

The United States Geological Survey monitors the flow of the Amargosa River at a gauge station near the Old Spanish Trail Road, west of Tecopa. The average flow of the river at this station is . This is from a drainage area of , much of which is noncontributing and all of which represents about 60 percent of the total Amargosa River drainage basin. The maximum flow recorded there was on August 16, 1983, and the minimum flow was on some days in some years.

Desert fish species

Amargosa River pupfish

The Amargosa River pupfish (Cyprinodon nevadensis amargosae) are one of the most notable residents of the Amargosa River. The species seems to be flourishing in the Amargosa Canyon, where its habitat has been safeguarded as a Wild and Scenic River, largely due to the efforts of the Amargosa Conservancy. They primarily reproduce in loose groups, with males displaying minimal aggression and frequently engaging in courtship behavior towards females. However, a subset of males in this population stake out and protect specific breeding territories along the warm, shallow areas of the river. These territorial males exhibit aggression and only occasionally engage in courtship behaviors towards females.

Amargosa speckled dace

The Amargosa River hosts three separate populations of speckled dace, situated in Oasis Valley near Beatty, Ash Meadows, and the Amargosa Canyon. An interesting revelation concerns the genetic makeup of these fish, indicating an unexpected level of connectivity along the river. Particularly noteworthy is the genetic blend observed in the speckled dace population of the Amargosa Canyon, incorporating traits from both the Oasis Valley and Ash Meadows populations. This suggests that during significant flood events, speckled dace are capable of traversing considerable distances along the Amargosa River, covering nearly 100 miles from Beatty to below Tecopa. These findings propose a level of interconnection among these populations not previously recognized in the pupfish. The name was first recorded in 1844 and is believed to refer to the alkaline water. The river is an ancient stream, following an antecedent canyon. Evidence of human habitation along the river goes back more than 10,000 years.

References

External links

Amargosa River Natural Area - BLM page
Friends of the River: Amargosa River
Amargosa River virtual tours
Amargosa Conservancy