Area of the Named Glaciers of Glacier National Park (GNP) and Flathead National Forest (FNF) Derived from Aerial and Satellite Imagery, 1966, 1998, 2005, 2015

These data represent a time series of the 37 named glaciers of Glacier National Park, MT, USA and two named glaciers in the Flathead National Forest. Glacier margins were digitized from aerial imagery taken in 1966, 1998, and 2005, and from satellite imagery taken in 2015/2016. Late summer imagery was used for analysis so that the extent of glacial ice was most easily determined after seasonal snow had melted from the glacier surface. Comparison between years shows a reduction in area from 1966 to 2015/6 for all glaciers, though rates of loss are variable. Establishing rates of glacier retreat, using the decreasing area of glacier ice, is key to understanding the Glacier National Park ecosystem and future state of resources. For instance, glacial meltwater provides critical habitat for endangered stream insects. More broadly, retreating glaciers are indicative of long term climate change and have hydrologic and ecologic importance to many park resources. Glaciers and their retreat are of great interest to park visitors and the American public and are part of Glacier National Park's appeal. The 2015 data reveal that 26 glaciers remain that are larger than 25 acres (0.1 square kilometer), which is used as a guideline for deciding if bodies of ice are large enough to be considered glaciers*. There were an estimated 150 glaciers in Glacier National Park in 1850. Information on appropriate use of these data and a description of the time series analysis is available at the USGS glacier time series web page: Other Resources: Endangered stream insects: Glacier retreat:
Glacier NameArea 1966 (m2)Area 1998 (m2)Area 2005 (m2)Area 2015 (m2)
Agassiz Glacier1,600,559.731,174,485.681,039,612.34736,669.75
Ahern Glacier589,185.63516,658.66511,939.47511,589.79
Baby Glacier *117,171.1380,880.3876,006.4775,562.60
Blackfoot Glacier1,832,451.351,625,124.381,630,173.411,498,505.92
Boulder Glacier *231,017.7348,774.1345,803.6435,298.01
Carter Glacier355,743.44269,013.88234,414.35224,773.89
Chaney Glacier563,819.03430,372.02359,686.58334,484.90
Dixon Glacier291,142.05166,983.60162,669.91125,831.13
Gem Glacier *29,140.1223,756.5123,527.2722,156.68
Grinnell Glacier1,020,200.39715,907.79615,568.81563,720.29
Harris Glacier *148,501.6040,263.7338,969.1034,260.89
Harrison Glacier2,059,376.841,846,232.521,697,714.471,661,456.75
Herbst Glacier *170,234.1650,794.7840,856.0131,886.02
Hudson Glacier *90,213.4555,762.1152,269.7652,167.62
Ipasha Glacier328,608.60228,254.45195,800.97194,738.75
Jackson Glacier1,280,508.24811,857.45803,342.15756,864.10
Kintla Glacier1,309,016.20972,884.73931,213.70877,726.05
Logan Glacier503,361.09387,547.07367,936.17219,016.92
Lupfer Glacier *126,375.8366,661.1663,843.5373,274.68
Miche Wabun204,468.79111,127.26107,464.55103,616.92
North Swiftcurrent Glacier *116,675.9784,546.1090,181.5286,305.30
Old Sun Glacier421,347.41349,137.54346,751.63341,077.95
Piegan Glacier280,151.62265,084.78250,768.05244,307.08
Pumpelly Glacier1,006,469.53910,631.86908,834.19902,787.30
Rainbow Glacier1,430,411.361,120,814.921,089,977.461,053,376.03
Red Eagle *134,709.8277,923.5877,923.5363,685.24
Salamander Glacier229,028.19181,688.65173,617.99176,108.77
Sexton Glacier400,493.53324,011.87312,762.43298,681.73
Shepard Glacier *250,678.8291,584.1975,248.6670,739.49
Siyeh Glacier306,295.75214,597.44214,663.20205,386.48
Sperry Glacier1,339,531.54953,104.43888,095.13801,670.14
Swiftcurrent Glacier221,786.00188,681.39176,239.36170,348.10
Thunderbird Glacier135,074.71121,885.69115,978.22107,012.09
Two Ocean Glacier *429,001.73193,677.91189,199.4475,172.89
Vulture Glacier408,034.38336,924.77329,180.45296,786.09
Weasel Collar Glacier558,088.21507,418.42506,575.45499,734.76
Whitecrow Glacier242,488.01124,759.84112,799.24103,824.86
Total GNP20,761,361.9815,669,815.6714,857,608.6113,630,605.96
Grant Glacier, FNF**347,753.17288,223.64285,758.27279,157.80
Stanton Glacier, FNF**532,357.36315,177.77301,630.87268,967.55
Total FNF880,110.53603,401.41587,389.14548,125.35
* based on 2015 data, this glacier is no longer considered "active" because its area is less than 25 acres; ** Flathead National Forest Glaciers; GNP: Glacier National Park; FNF: Flathead National Forest; Full USGS ScienceBase data release:; Fagre, D.B., McKeon, L.A., Dick, K.A., and Fountain, A.G., 2017, Glacier margin time series (1966, 1998, 2005, 2015) of the named glaciers of Glacier National Park, MT, USA: U.S. Geological Survey data release,