Mount Washington has been eroded over time and is now very dissected, with its inner contents exposed and U-shaped canyons and cirques. In the late Pleistocene, large glaciers extending more than to the east and west carved cirques into the slopes of the volcano. The George Lake and Dry Creek cirques, which face north and northeast, respectively, show evidence of holding glaciers similar to those documented at Canyon Creek cirque on Three Fingered Jack with moraines. Wood and Kienle (1990) estimate that Mount Washington once extended to an elevation of , with an elevation of above the basalt lava field surrounding it.