About 10,000 years ago, Lake Bonneville was a vast freshwater lake larger than the present Great Salt Lake, stretching from the Wasatch Mountains at Salt Lake City to the Toano and Goshute Mountains. During the last major glacial period in North America, which began about 23,000 years ago, colder temperatures and a wetter climate caused its water level to rise until it was over 1,000 feet deep and covered 51,530 square miles, an area the size of Arkansas. Around 15,000 years ago, this location lay more than 500 feet underwater, and Pilot Peak stood as a small island in a lake teeming with fish. About 14,500 years ago, water bursting through a break in a natural dam along the lake's northern shore lowered the lake more than 300 feet in only a few months, and the floodwaters deepened the Snake River Canyon in Idaho. Over the next 5,000 years, a warmer and drier climate caused the lake to shrink further, leaving beach terraces on the surrounding hills, especially east toward Wendover, and the Great Salt Lake as the remnant of this once immense lake.