Flora and Fauna
A wide variety of plants and animals find homes within Utah’s great range of elevations (more than 11,000 feet). Regardless of the precipitation, the environment is harsh, and most plants and animals have had to adapt to endure the challenging climate. To help simplify and understand the different environments, some scientists use the Merriam system of life zones, which offers a concise way to get an overview of Utah’s vegetation and animal life. Because plants subsist on rainfall, which is determined largely by elevation, each life zone can be identified with an elevation range. These ranges are not exact, however, due to the different rainfall patterns and evaporation rates.
Utah’s lowest elevations lie in the Lower Sonoran Life Zone (below 3,500 feet). This zone is found in the Mojave Desert, which extends into the southwest corner of the state. Most of Utah’s northern deserts and canyonlands are considered part of the Upper Sonoran Life Zone (3,500–5,500 feet). As rainfall increases near mountain ranges, the Transition Life Zone (5,500–8,000 feet) begins. The Transition Zone is best developed on the High Plateaus and the Uinta Mountains and less so in the Great Basin and the Wasatch Range. At successively higher elevations are the Canadian Life Zone (8,000–10,000 feet), the Hudsonian Life Zone (10,000–11,000 feet), and the Alpine Tundra Life Zone (above 11,000 feet).
In the southern Lower Sonoran deserts near St. George, fewer than eight inches of rainfall yearly. Creosote bush dominates the plantlife, though you’re also likely to see rabbitbrush, snakeweed, blackbrush, saltbush, yucca, and cacti. Joshua trees grow on some of the higher gravel benches. Flowering plants tend to bloom after either the winter rains (the Sonoran or Mexican species) or the summer rains (the Mojave or Californian species).
In the more temperate Upper Sonoran Zone, shadscale—a plant resistant to both salt and drought—grows on the valley floors and the lower slopes of the Great Basin, Uinta Basin, and canyonlands. Commonly growing with shadscale are grasses, annuals, Mormon tea, budsage, gray molley, and winterfat. In salty soils, more likely companions are greasewood, salt grass, and iodine bush. Nonalkaline soils, on the other hand, may have blackbrush as the dominant plant. Sagebrush, the most common shrub in Utah, thrives on higher terraces and in alluvial fans of nonalkaline soil. Grasses are commonly found mixed with sagebrush and may even dominate the landscape. Piñon pine and juniper, small trees often found together, can grow only where at least 12 inches of rain falls annually; the lower limit of their growth is sometimes called the “arid timberline.” In the Wasatch Range, scrub oaks often grow near junipers.
As elevation rises and rainfall increases, you’ll see growing numbers of ponderosa pine and chaparral in the forest. The chaparral association includes oak, maple, mountain mahogany, and sagebrush. Gambel oak, juniper, and Douglas fir commonly grow among the ponderosa in the Uintas and the High Plateaus.
Douglas fir is the most common tree within the Canadian Zone in the Wasatch Range, the High Plateaus, and the northern slopes of the Great Basin Ranges. In the Uintas, however, lodgepole pine dominates. Other trees of the Canadian Zone include ponderosa pine, limber pine, white fir, blue spruce (Utah’s state tree), and aspen.
Strong winds and a growing season of less than 120 days prevent trees from reaching their full size at higher elevations. The Hudsonian Zone receives twice as much snow as the Canadian Zone just below. Often gnarled and twisted, Engelmann spruce and subalpine fir grow in the cold heights over large areas of the Uintas and Wasatches. Limber and bristlecone pines live in the zone, too. Lakes and lush subalpine meadows are common.
Only grasses, mosses, sedges, and annuals can withstand the rugged conditions atop Utah’s highest ranges. Freezing temperatures and snow can blast the mountain slopes even in midsummer.
Most desert animals retreat to a den or burrow during the heat of the day, when ground temperatures can reach 130°F. Look for wildlife in early morning, during late afternoon, or at night. You may see kangaroo rat, desert cottontail, black-tailed jackrabbit, striped and spotted skunks, kit fox, ringtail cat, coyote, bobcat, mountain lion, and several species of squirrels and mice. Birds include the native Gambel’s quail, roadrunner, red-tailed hawk, great horned owl, cactus wren, black-chinned and broad-tailed hummingbirds, and rufous-sided towhee. The endangered desert tortoise lives here, too, but faces extinction in a losing battle with livestock, which trample and graze on the tortoise’s environment.
The rare Gila monster, identified by its beadlike skin with black and yellow patterns, is found in the state’s southwest corner. Sidewinder, Great Basin, and other Western rattlesnakes are occasionally seen. Also watch for other poisonous creatures; scorpions, spiders, and centipedes can inflict painful stings or bites. It’s a good idea when camping to check for these unwanted guests in shoes and other items left outside. Be careful, too, not to reach under rocks or into places you can’t see.
In the more temperate Upper Sonoran Zone, you’ll see plenty of desert wildlife, though you might also see Utah prairie dog, beaver, muskrat, black bear, desert bighorn sheep, desert mule deer, and the antelope-like pronghorn. Marshes of the Great Basin have an abundance of food and cover that attract waterfowl; species include whistling swan, Great Basin Canada goose, lesser snow goose, great blue heron, seagull (Utah’s state bird), common mallard, gadwall, and American common merganser. Chukar (from similar desert lands in Asia) and Hungarian partridge (from eastern Europe and western Asia) thrive under the cover of sagebrush in dry-farm areas. Sage and sharp-tailed grouse also prefer the open country. Rattlesnakes and other reptiles like the Upper Sonoran Zone best.
Not surprisingly, few fish live in the desert. The Great Salt Lake is too salty to support fish life; the only creatures that can live in its extremely saline water are bacteria, a few insect species, and brine shrimp, which are commercially harvested. The Colorado River, which cuts through southeastern Utah, supports a number of fish species, several of which are endemic to the river and are now considered endangered.
In the thin forests of the Transition Zone, squirrels and chipmunks rely on pinecones for food; other animals living here include Nuttall’s cottontail, black-tailed jackrabbit, spotted and striped skunks, red fox, coyote, mule deer, Rocky Mountain elk (Utah’s state mammal), moose, black bear, and mountain lion. Moose did not arrive until the 1940s, when they crossed over from Wyoming; now they live in northern and central Utah. Merriam’s wild turkey, originally from Colorado, is found in oak and ponderosa pine forests of central and southern Utah. Other birds of the Transition Zone include Steller’s jay, blue and ruffed grouse, common poorwill, great horned owl, black-chinned and broad-tailed hummingbirds, gray-headed and Oregon juncos, white-throated swift, and the common raven. Most snakes, such as the gopher, hognose, and garter, are harmless, but you may also come across Western rattlers.
Utah has more than 1,000 fishable lakes and numerous fishing streams. Species range from rainbow and cutthroat trout to large mackinaw and brown trout to striped bass, walleye, bluegill, and whitefish. Bear Lake in extreme northern Utah is home to the Bear Lake whitefish, Bonneville whitefish, Bonneville cisco, and Bear Lake sculpin—all are unique to Bear Lake and its tributaries. Because of their restricted range, they are vulnerable to extinction from habitat alteration due to water management of Bear Lake and its tributaries.
Deer and Rocky Mountain elk graze in the Canadian Zone but rarely higher. Smaller animals of the high mountains include northern flying squirrel, snowshoe rabbit, pocket gopher, yellow belly marmot, pika, chipmunk, and mice.
Even higher, in the Hudsonian Zone, on a bright summer day the trees, grasses, and tiny flowering alpine plants are abuzz with insects, rodents, and visiting birds. Come winter, though, most animals will have moved to lower, more protected areas. Few animals live in the true alpine regions. White-tailed ptarmigan, recently introduced to Utah, live in the tundra of the Uinta Mountains.
© W.C. McRae and Judy Jewell from Moon Utah, 9th Edition