Alvord Desert

The Alvord Desert is a dry lake in Harney County, southeastern Oregon, at the eastern foot of Steens Mountain. The mountain rises more than a mile above the playa. Streams flow onto the playa, but the basin has no outlet. The water evaporates, leaving salt minerals on the surface. The playa can flood in wet periods but is dry for much of the year. When dry, its broad, flat surface is used for land sailing, glider flying, motoring, and camping. Researchers have also used the playa to study dust devils and test sensors for future Mars exploration. More than 35 sq mi (91 km2) of the playa lie within the Alvord Desert Wilderness Study Area.

The desert is named after General Benjamin Alvord, who served as commander of the U.S. Army's Department of Oregon during the American Civil War.

The Wadatika, a Northern Paiute band, spent part of late summer and early fall in the Alvord Desert and wintered near Malheur Lake. The Burns Paiute Tribe says its members are primarily descendants of the Wadatika. A 1975 survey of the wider Alvord Basin recorded 224 archaeological sites and 217 identifiable stone points. Some points found around the Alvord Desert playa were dated by style to about 8000 to 5000 BCE, when researchers believed it held a lake. Smaller points thought to be arrowheads from roughly the past 2,000 years were found on an alluvial fan at the playa's north edge.

The Alvord Desert experiences a cold desert climate (Köppen BWk). The area receives very little rainfall throughout the year due to the rain shadow created by the Coast and Cascade mountain ranges as well the adjacent Steens Mountain. A 2008 U.S. Geological Survey report estimated mean annual precipitation in the Alvord Desert at less than 4 inches (100 mm).

Winter temperatures in the Alvord Basin are moderated through airflow from the south that stops the temperature from dropping too heavily. While many areas in the Oregon High Desert frequently dip below 0 °F (18 °C) through the winter months, the Alvord Desert rarely sees these frigid temperatures. On average, highs will commonly reach between 40 and 50 °F (4 and 10 °C), with a few rare instances where the temperature fails to break 32 °F (0 °C). At night, the temperature falls to between 20 and 30 °F (7 and 1 °C), but will not normally fall much further unless Arctic air masses arrive. The basin sees a moderate amount of its rainfall in the winter months from storms coming off the Pacific Ocean while the strong winter jet stream is aimed at the Pacific Northwest. Storms that are strong enough to bring moisture to the southeastern area of Oregon are usually related to tropical storms feeding from the Hawaiian Islands. Snow does sometimes occur in the rare instances when cold air from the Arctic to the north meets a strong flow of moisture from the Pacific to the West.

Spring is when the bulk of precipitation falls from thunderstorms. These storms are attributed to the rainfall in April, May, and June that form in the south and move their way north across the desert and surrounding sagebrush plains. Clear nights continue to bring cold overnight temperatures which commonly drop to between 30 and 45 °F (1 and 7 °C), but afternoon warming raises temperatures to between 50 and 60 °F (10 and 16 °C) in early spring and 70 and 80 °F (21 and 27 °C) in late spring. This warming can help trigger thunderstorms in combination with the unstable spring atmosphere. Extremes in temperature can still be seen at this time of year where temperatures have fallen to 0 to 10 °F (18 to 12 °C) in March, and climbed to over 100 °F (38 °C) in early June. Rainfall turns the playa into a small lake, and for a short time, makes travel across it difficult.

Location: United States.

Desert data from Wikidata (CC0).