The Salt Lake City area looked something like this 15 thousand years ago, when glaciers covered much of the mountainous western United States and fed large lakes. Lake Bonneville, the largest such lake in the western U.S., covered much of western Utah and eastern Nevada. At its peak, it was some 900 feet deeper than the modern Great Salt Lake and flooded what is now the Salt Lake Valley; only the extreme eastern foothill regions of the City would escape a repeat flooding. The Valley occupies the lower left-hand portion of the picture; the familiar Salt Lake area canyons (City Creek, Emigration, Parley's, Mill Creek, and Big and Little Cottonwood) "drain" into the giant lake. "Point of the Mountain", the dividing line between Salt Lake and Utah Valleys, is the peninsula in the lower center.