<P> The study and definition of ecoregions can also indicate the boundaries of the Great Basin Desert . In 1987, J.M. Omernik defined a desert ecoregion between the Sierra Nevada and Wasatch Range, naming it the "Northern Basin and Range" ecoregion . In 1999, the U.S. EPA renamed the "Northern Basin and Range" to "Central Basin and Range" and the "(Snake River) High Desert" to the "Northern Basin and Range". The World Wildlife Fund adopted the Basin and Range ecoregions from Omernik, but excised a small region of high - altitude areas which contain Holocene refugia, from the former "Northern Basin and Range" ecoregion and renamed it the "Great Basin Shrub Steppe". Although the EPA had refined the boundaries of the Central Basin and Range ecoregion by 2003, when USGS geographer Christopher Soulard wrote his reports on the region, his maps used the 1999 boundary for the "Central Basin and Range", which is essentially the same as the "Great Basin Shrub Steppe". He states that the Great Basin Desert is "encompassed within" that area . </P> <P> This article describes the general ecology of the region, including the high - elevation areas, and does not rely on minor differences in the definitions of the ecoregion or desert . See Great Basin montane forests for more specific details on the high - elevation ecoregion . </P> <P> The climate of the Great Basin desert is characterized by extremes: hot, dry summers and cold, snowy winters; frigid alpine ridges and warm, windy valleys; days over 90 ° F (32 ° C) followed by nights near 40 ° F (4 ° C). This is the climate of the high desert . </P> <P> The Great Basin desert climate begins with the Sierra Nevada in eastern California . Rising 14,000 feet (4,300 m) above sea level, this mountain range casts a large rain shadow over the desert . Weather coming in from the Pacific Ocean quickly loses its moisture as rain and snow as it is forced up and over the steep mountains . By the time it reaches the east side of the mountains, little moisture is left to bring to the desert . The rain shadow effect is more pronounced closer to the Sierra Nevada, with yearly precipitation in the Great Basin desert averaging 9 inches (230 mm) in the west and 12 inches (300 mm) inches in the east . Moisture that manages to reach the ecoregion tends to precipitate as rain and snow in higher elevations, primarily over the region's long, parallel mountains . Ultimately, any precipitation that falls within the desert fails to drain either to the Atlantic Ocean or to the Pacific Ocean (thus the term "basin"). Instead, precipitation drains to ephemeral or saline lakes via streams, or disappears via evaporation or absorption into the soil . The desert is the coldest of the deserts in North America . </P>

What is the climate of the great basin