More than 10,000 years ago, much of the Great Basin contained the deep, fresh water of Lake Bonneville. What remains today is Lake Bonneville’s briny remnant: The Great Salt Lake.
Except for the mountains, which were pushed upward by forces deep within the earth’s crust, Tooele County’s landscape was formed by the pernicious power of wind, water and time. Although much of the county lies within the Great Salt Lake Desert, evidence of water’s strength can be seen everywhere. On the Oquirrh Mountains above Tooele Valley, there are distinct terraces and scarps where waves from Lake Bonneville crashed against the mountains. The visible lines of erosion, some more than 1,000 feet above the valley floor, tell of a wilder time in the region, when most of Utah was covered with water, and glaciers spilled down from the mountains. Such erosion lines are also visible on most of the county’s 11 other mountain ranges.