Utah includes six geographic regions. Around half of Utah is made up of the Colorado Plateau, where erosion has carved deep, colorful canyons, buttes, and mesas. The western third of the state is part of the Great Basin. This is a broad, flat, desert-like area with some mountain peaks. Streams and rivers in this region often disappear in the dry season. The lowest point in Utah (2,000 feet/610 meters above sea level) is at Beaverdam Creek in Washington County, in the southwest corner of the state. In the northeast part of the state are the Middle Rockies. They are made up of three mountain ranges—Bear River, Wasatch, and Uinta, which include the highest point in Utah—Kings Peak in the Uintas (13,528 feet/4,126 meters). Most of Utah’s major cities are located in a geographic areas called Wasatch Front, which lies at the western edge of the Wasatch Range. There are also two smaller regions - the Kaiparowits Plateau, in southern Utah, and the Overthrust Belt, in the north-central part of the state. These areas are rich in fossil fuels.
Much of Utah is dry, but it also has several large rivers. These are the Colorado River in eastern Utah; the Bear, Weber, Provo, Jordan, and Sevier rivers in the central and western part of the state; and the Raft River and Goose Creek in the northwestern corner of the state. Irrigation and water conservation are very important for Utah. There are many dams, reservoirs, canals, pipelines, and flowing wells in the state, including two large dams at Glen Canyon and Flaming Gorge. The largest lake in the state is the Great Salt Lake. This is all that remains of a vast Pleistocene lake (about 2,600,000 to 11,700 years ago) which once covered an area as large as Lake Michigan. Over time, the lake evaporated, leaving behind the Great Salt Lake, saline Sevier Lake, and freshwater Utah Lake. Other lakes include Utah Lake, Bear Lake (shared with Idaho), and Lake Powell, which was created by the building of the Glen Canyon Dam on the Colorado River.
Utah lies to the rainshadow of several large mountain ranges. This means that much of Utah is dry and desert-like. Southwestern Utah is the wettest part of the state. It has a warm, subtropical climate and so is sometimes called Utah’s “Dixie.” The southern part of the Colorado Plateau has cool, dry winters and wet summers, with frequent thunderstorms. Northern Utah is cooled by air from the pole and the northern Pacific Ocean, and is the coolest part of the state. The average temperature is in the low 70s °F (about 21 °C) in July, while in winter the average temperature is slightly below freezing, except in Dixie. However, temperatures vary widely around the state. In Salt Lake City, temperatures in July reach highs of 90 °F (32 °C) or above. Average rainfall is about 11 inches (280 mm) a year, but is as high as 50 inches (1,280 mm) in the Wasatch Mountains and less than 8 inches (200 mm) over the Great Salt Lake Desert. Mountain ski resorts receive more than 10 feet (3 meters) of snow, but in other areas the average yearly snowfall is about 4.5 feet (1.5 meters). The record high temperature, 117°F (47°C), was set at St. George on 5 July 1985; the record low temperature, –69°F (–56°C), in Peter's Sink, on 1 February 1985.
