Lake Bonneville: Geology of northern Utah Valley, Utah

Lake Bonneville was a vast Pleistocene lake that covered 20,000 square miles in northwestern Utah and had a maximum depth of about 1,000 feet. It was a body of water comparable in size to modern Lake Michigan.

Surveys of the unconsolidated deposits in the Lake Bonneville basin utilize the same methods used in studies of hard rocks, namely: separation of the deposits into mappable units and contacts between formations; observations of lateral and vertical changes in lithology; and plotting of these data on the map.