Tony Grove Lake is a national forest recreation site for camping, hikes, caving, and winter sports located in Logan Canyon between Garden City and Logan, Utah.  Here in the higher portions of the Bear Lake Range, glaciers carved U-shaped valleys over the last 100,000 years.  Tony Grove Lake sits in the depression at the head of one such U-shaped valley.

The cliff wall to the west of the lake was formed in rock that long predates the glaciers by hundreds of millions of years.  The upper gray-white walls, made of ancient sea deposits metamorphosed into dolomite, date from a time when this area was just off the edge of a continent around 430 million years ago. In some places, the debris of the dolomite runs downhill in a slope to the lake.  In other areas along the cliff, the older (460 million y/o) tan, brown and orange quartzite peaks out from under the layer of dolomite.