How are the salt flats formed?
In the arid environment of Utah’s West Desert, many people are surprised the answer involves water. During the last Ice Age over 12,000 years ago, ancient Lake Bonneville was the size of Lake Michigan. It covered one-third of present-day Utah and parts of neighboring states. You can see traces of the shorelines, representing different levels of the receding lake, etched into the mountains throughout Utah. The Bonneville Salt Flats and the Great Salt Lake are remnants of ancient Lake Bonneville. When the waters receded at the end of the last Ice Age, large concentrations of dissolved minerals were deposited in surrounding soils. These minerals include gypsum (commercially used to make household wallboard) and halite (common table salt). The Bonneville Salt Flats are comprised of approximately 90% salt. Today, ground water flows from the surrounding area, picks up dissolved minerals along the way, and percolates up to the surface of the flats. When temperatures rise in the late spring an
