Excerpts from the report Introduction: Increasing and often conflicting demands for water in the West have heightened public awareness of the need for sound management decisions concerning water. Although the West's high mountain ranges hold a vast snowpack that provides 50 to 80 percent of the year's water supply, nature cannot be relied upon to provide an uninterrupted, dependable supply of meltwater to meet all the downstream requirements. To moderate this variability, reservoirs and canals have been built to serve the growing needs of agriculture, industry, and communities. But successful water management begins with an adequate knowledge of the primary source of water in the West: snow. This booklet describes the cooperative snow survey program. It is intended to provide the general public as well as water resource professionals with a better understanding of the importance of snow, snowpack surveys, and water supply forecasting in natural resources management.