Technical Abstract: Snow and ice features can cover 44 percent of the world's land areas at any one time, and as such, can have significant effects on radiation exchange, hydrologic budget, and climate. Because of the large and remote regions covered, remote sensing of snow and ice has become the only way continuous monitoring can be done. Various portions of the electromagnetic spectrum have been successfully used. Gamma radiation is used for estimates of sno water equivalent in confined regions. Visible imagery is the most reliable approach for measuring the areal extent of snow cover. Passive microwave approaches have shown the most potential for snow water equivalent measurements over large areas. Both thermal infrared and active microwave approaches have significant potential, but are more difficult to analyze. Integration of data form two different sensors has a strong potential for increasing the information available about the snowpack.