Lake Bonneville

The sign claims more than the lake can hold. Lake Bonneville was the largest Ice Age lake in the Great Basin, about 20,000 square miles at its peak and nearly the size of Lake Michigan, but glacial Lake Agassiz, fed by the melting ice sheet on the northern plains, was several times larger. The two other remnants the sign leaves unnamed are Utah Lake and Sevier Lake. The shoreline it points to is the Bonneville level, cut where the lake stood before it overflowed at Red Rock Pass.

What the plaque says

Lake Bonneville 20,000 years ago, this land was under water. Not far to the north, you can see the old shore of Lake Bonneville. Formed in a basin from which no river reached the ocean, this became the largest lake in North America. Finally the lake rose high enough to overflow into the Snake River. Then after the climate got drier, and the great basin of Utah and Nevada became mostly a desert, the lake receded. Salt Lake and two other remnants are all that are left of this old 20,000 square mile lake. 317 Text prepared by the Idaho Historical Society Marker made & installed by Idaho Transportation Department

Where it stands

More markers nearby

• Curlew Valley — 13 mi
• Twin Springs — 15 mi
• Kelton Cemetery — 25 mi