A comprehensive inventory of perennial snow and ice in Glacier National Park in 2005

These polygon features represent a comprehensive inventory of perennial snow and ice on the landscape in Glacier National Park (GNP) in 2005. The imagery used to delineate perennial snow and ice was taken late season, therefore, all snow and ice present on the landscape is assumed to be perennial. Whether each polygon is "perennial snow and ice" or "active glacial ice" is included. Active glacial ice is defined as perennial ice patches that exhibit characteristics such as bergschrunds and extensive crevassing. This release does not include the 2005 extent of the 37 named glaciers in GNP, which have been previously published. Polygons were digitized based on National Agricultural Imagery Program (NAIP) imagery acquired in 2005, imagery acquired by the National Park Service in 2004 to assess the extent of 2003 wildfires, and border Imagery from the Department of Homeland Security acquired in 2009. Digitization was completed by Adam Clark (USGS) and Kevin Jacks (USGS). Perennial snow and ice was digitized at 1:2000 scale.