The dry, salt-encrusted bed of prehistoric Lake Bonneville is apparent in this south-southeast-looking, low-oblique photograph. The Great Salt Lake Desert is a small remnant of the prehistoric lake that covered portions of present-day Idaho, Nevada, and Utah during the last ice age 12 000 years ago. Parts of the Great Salt Lake Desert are sometimes covered with shallow ponds as a result of above-normal precipitation. When these small ponds dry up, the thick, salt-encrusted desert floor is increased. The extreme western portion of Great Salt Lake is visible in the upper left of the photograph.