Mountain glaciers are good indicators of global climate change. Glaciers are masses of ice found on land that are thick enough to flow under their own weight or that show evidence of past movement. Documenting the retreat of tropical glaciers is difficult because they are often located in remote areas with steep terrain and inclement weather. However, today's computerized mapping technologies, including remote sensing and geographic information systems (GIS), can complement field studies in tracking changes of these remote glaciers. In fact, the Intergovernmental Panel on Climate Change (IPCC) has recommended the use of satellite remote sensing to document glacier change.