Sperry Glacier

Infobox_Glacier | glacier_name = Sperry Glacier


caption =
type = Mountain glacier
location = Montana, U.S.
coordinates = coord|48|37|24|N|113|45|38|W|type:glacier
area = .83 km² (1993)
length =
thickness =
terminus = Talus
status = Retreating

Sperry Glacier is located in Glacier National Park (U.S.) in the U.S. state of Montana. The glacier is situated on the north slopes of Gunsight Mountain, immediately west of the Continental Divide. [cite web| title =Sperry Glacier, USGS Lake McDonald East (MT) Topo Map| work =| publisher =TopoQuest| date =| url =http://www.topoquest.com/map.php?lat=48.62317&lon=-113.76056&datum=nad27&zoom=4| accessdate = 2008-05-15] Although many geologic features of Glacier National Park were formed during the much longer period of glaciation ending over 10,000 years ago, Sperry Glacier, like all the glaciers in the park today, is a product of the recent Little Ice Age, the period of cooler average temperatures starting in about the 13th century and concluding in the mid-19th century.

Once one of the largest glaciers in the park, the surface area of Sperry Glacier has retreated 75 percent since the mid 1800s. 1993 measurements of the surface area of the glacier resulted in an estimated area of .83 km², whereby the glacier is estimated to have covered an area of 3.76 km² at the end of the Little Ice Age in the mid 1800s. [cite web| title =Glacier Retreat in Glacier National Park, Montana| work =| publisher =U.S. Geological Survey| date =| url =http://www.nrmsc.usgs.gov/research/glacier_retreat.htm| accessdate = 2007-01-12] The glacier is named for Lyman B. Sperry, a professor from Oberlin College, who in 1895 was a party in an exploration of the region where the glacier is located. [cite web| title =Discovery and Exploration| work =| publisher =National Park Service| date =| url =http://www.cr.nps.gov/history/online_books/glac/adhi1b.htm| accessdate = 2007-01-12]

Like all other glaciers in the park, Sperry has significantly retreated, though it leaves many minor glacial features, including large moraines and streams and lakes colored a milky aqua from glacial flour. Unlike the more famous Grinnell Glacier, Sperry is high above the lakes it feeds, so no icebergs form.

Visiting the Glacier

Hikers may wish to spend the night at Sperry Chalet or its neighboring backcountry campground (requires a permit) before the hike to Sperry Glacier. Although it is seven miles round-trip from the Chalet (about eight from the campground), it is a steep walk, rising 1,600 feet (487 m) in just 2.5 miles (4 km). Invisible from the rocky slopes below, a series of green glacial cirques with trickling streams and waterfalls and clear lakes reflecting snow fields and mountain peaks leads to a steep and narrow stone staircase cut into the stone ridge of Comeau Pass. The view from the top of the steps is panoramic, encompassing Mt. Brown, Edwards Mountain, and Little Matterhorn.

Reaching the glacier itself involves crossing a wide rock scrabble, snow fields, and the colorful but sometimes tricky glacial moraine. Following the rock cairns and other trail markers will ensure the best footing and easiest routes. Ranger-led hikes are available, starting at the chalet.

References cited

ee also

*Glacier National Park (U.S.)
*Retreat of glaciers since 1850
*List of glaciers