Western Working Lands Snapshot | The Great Basin

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The Great Basin is characterized by dry valleys. Photo: NPS

The Great Basin covers much of Nevada and parts of Idaho, California, Utah, and Oregon. Photo: NPS

This month’s Western Working Lands “Snapshot” introduces us to the Great Basin. This fascinating landscape is known for its basin and range topography and its unique hydrological features. Read on to learn more about this captivating landscape.

Led by the USDA’s Natural Resources Conservation Service, Working Lands For Wildlife uses voluntary incentives to benefit America’s agricultural producers and at-risk wildlife.

By Brianna Randall

Definition

Map of North America’s watersheds. The orange section is the Great Basin, where water does not drain to the ocean. Map: WikiCommons

The Great Basin of the western United States is a 200,000 square-mile desert ecosystem—an area larger than most countries—where all of the water drains “inward” into terminal lakes or underground, rather than “outward” into the ocean.

Location

The Great Basin spans most of Nevada and portions of Oregon, Idaho, Utah and California. Its geographic borders are the Wasatch Mountains to the east, the Sierra Nevada and Cascade Ranges to the west, the Snake River Basin to the north, and the Mojave Desert to the south.

Notable Landmarks

Known for its dry climate and unique topography, this region contains mountains, deserts, woodlands, and riparian areas. The Great Basin also includes these noteworthy landmarks:

• Lowest point in North America: Badwater Basin in Death Valley at 282 feet below sea level
• Highest point in the contiguous United States: Mount Whitney in the Sierra Nevada at 14,505 feet above sea level
• Largest saltwater lake in the Western Hemisphere: Great Salt Lake in Utah
• Largest alpine lake in North America: Lake Tahoe in California and Nevada

Basin and Range Topography

The Great Basin is characterized by a series of tall, rugged mountain ranges that parallel low, broad valleys (or basins). The valleys are usually desert shrublands with elevations around 4,000 feet, while the mountain peaks often soar above 10,000 feet.

This type of “basin and range” topography is created as the Earth’s crust spreads apart. Mountains form where the crust is pushed upward along moving fault lines, while basins appear where the crust stretches and becomes thinner.

Aerial view of basin and range topography. The darker areas are forested slopes on mountain sides, the lighter areas are dry valley bottoms. Photo: WikiCommons

Climate

Because it spans diverse elevations and latitudes, the climate varies throughout the Great Basin. Most of the region experiences warm summers, cold winters, and arid conditions. Situated in the rain shadow of the Sierra Nevada and Cascade mountain ranges, the Great Basin’s average annual precipitation is just 6 to 12 inches and mostly falls as snow.

Ten thousand years ago, many of the valleys in the Great Basin were covered with water from large lakes formed by melting ice. Today, only remnants of those vast lakes remain, such as the Great Salt Lake, Pyramid Lake, and Walker Lake.

The Great Basin is characterized by dry valleys. Photo: NPS

Vegetation

The Great Basin is dominated by sagebrush, salt desert shrublands, pinyon-juniper woodlands, and other mixed shrub- and woodlands.

In the higher elevations where temperatures are cooler and precipitation rates are higher, alpine and sub-alpine forests dot the mountainsides. These areas are where you can find bristlecone pines, the oldest organisms on Earth that can live nearly 5,000 years! These high-elevation forests transition to pinyon-juniper woodlands in the foothills. At the bottom of some valleys, the soil becomes salty and so dry that only certain types of heat- and salt-tolerant shrubs grow.

Many of the Great Basin’s mountains support high-elevation plant communities as shown in this photo of Mount Wheeler. Photo: NPS

Animals

From rattlesnakes and tarantulas to golden eagles and sage grouse, the Great Basin is home to diverse species of wildlife. Abundant rodents scamper across the landscape, including black-tailed jackrabbits and kangaroo rats, while larger mammals native to the region include pronghorn, mule deer, mountain lions, coyotes and bighorn sheep.

Even shorebirds and salamanders can be found in the rare-but-precious wet places, like springs, creeks, playas, or terminal lakes. These “emerald isles” in the Great Basin’s deserts provide critical food, water, and shelter for much of the region’s wildlife.

The Great Basin Rattlesnake is just one of the many wildlife species that call this rugged landscape home. Photo: USFWS

People

Many different Native American tribes made their home in the Great Basin, including the Ute, Shoshone, Paiute, and Navajo. Some of these traditional cultures used horses, while others traveled by foot. Tribes typically moved frequently during the summer in search of food and water resources, while maintaining winter villages along valley bottoms.

Until the railroad came through in the late 1800s, the Great Basin’s endless rows of scorching valleys and steep mountains created barriers for early Americans migrating west. This rugged landscape is one of the most sparsely populated parts of the United States.

The Great Basin’s two largest cities are Salt Lake City, Utah and Reno, Nevada. Livestock ranching and mineral extraction (including gold, silver, mercury, lithium, copper, and iron) are the main economic drivers for small communities in this region.

Salt Lake City, Utah is one of the largest cities in the Great Basin. Photo: WikiCommons

Conservation Concerns

Altered wildfire regimes represent the most widespread challenge to conserving the Great Basin’s native ecosystems. The proliferation of invasive species like cheatgrass has increased fire size and frequency relative to historic rates, especially at lower elevations. Ironically, at upper elevations, fire suppression efforts have allowed pinyon-juniper woodlands to become thicker and spread into imperiled sagebrush shrublands. These changes threaten native wildlife, and also impact rural economies—like ranching and recreation—that rely on healthy sagebrush ecosystems.

This animated graphic shows fire size and frequency in the Great Basin from 1984-2017. Invasive annual grasses are one of the main drivers of the increased fire activity seen in this graphic. Developed by Eric Jensen, Colorado State University.

Another threat to people and wildlife in the Great Basin is dwindling freshwater supplies, which are necessary to meet growing demand from cities, industry, and irrigated agriculture.

Luckily, proactive conservation partnerships like USDA-NRCS Working Lands for Wildlife are working with private landowners to address these challenges with creative, voluntary solutions that maintain this vast and beautiful landscape for future generations.

>Read more Western Working Lands Snapshots<<