These ranges' ice-clear mountain lakes are typically pools that have collected in glacial cirques. The Wind River and Beartooth ranges, on the other hand, are thought to have been nearly buried under ice sheets during the last glaciation, much as Yellowstone National Park was. Greater Yellowstone still has glaciers, although they are probably not remnants of the mighty ice fields that carved this country into its lovely, rugged shape. Geologists believe those glaciers melted and these formed later. The Tetons harbor several small glaciers, including one on the Grand itself.
Glaciers grow and shrink with small fluctuations in climate.
Photos taken of the Grand in the late 1800s show a much larger glacier below its north face than the one you see there today. The Wind River Mountains, in the seldom-visited southeast corner of Greater Yellowstone, get the glacier prize. Their extremely high altitude has allowed the formation of at least 24 named glaciers. This range has the largest glaciers in the lower 48 states. We refer, as many do, to a Greater Yellowstone ecosystem, as though it were a homogeneous place.