Such are the Great Salt Lake and Carson deserts in the north, the Mohave and Colorado and Amargosa (Death Valley) deserts of the south-west.
Industrially Great Salt Lake is of a certain importance.
The Upper Sonoran life-zone comprises south-eastern Montana, central, eastern and north-eastern Wyoming, a portion of south-western South Dakota, western Nebraska and Kansas, the western extremity of Oklahoma, north-western Texas, eastern Colorado, south-eastern New Mexico, the Snake plains in Idaho, the Columbia plains in Washington, the Malheur and Harney plains in Oregon, the Great Salt Lake and Sevier deserts in Utah, and narrow belts in California, Nevada and Arizona.
In 1843 General John C. Fremont with Kit Carson and three others explored the Great Salt Lake in a rubber boat.
On Gunnison and Hat islands in Great Salt Lake are valuable guano deposits which are used as fertilizers for vegetable gardens.
Almost half a century later, in the winter of 1824-25, James Bridger, a trapper, discovered the Great Salt Lake while seeking the source of the Bear river.
As Great Salt Lake City grew all landholders benefited, either by the location of their property or because of its size, the smaller lots being closer to the business centre and the larger tracts being in the outlying districts.
With Brigham Young and his little band of Mormon followers (between 140 and 150 members)., who entered the Great Salt Lake Valley in July 1847, begins the story of settlement and civilization (see Mormons).