Public concern over the consequences of augmenting the mountain snowpack by cloud seeding has set researchers to reworking data in an effort to determine the influence of modest increases of snow on the environment. One such set of precipitation, runoff, and vegetative production data from the Black Mesa Experimental Range has been analyzed statistically to quantitatively define relationships of peak snowpack to hydrologic characteristics and herbage production. The experimental area is located west of Gunnison, Colo., on National Forest land at an elevation of 9,800 ft. The vegetative cover is broadly classified as aspen, spruce-fir, and herbaceous. The last, commonly referred to as Thurber fescue grassland, comprises approximately 50% of the area. A mixed grassweed complex occupies the largest area within the herbaceous type. Needlegrasses (Stipa lettermanii Vasey and S. columbiana Macoun) and Idaho fescue (Festuca idahoensis Elmer) are frequently found components. Hummocky areas, termed mima mounds, support a variety of cover types. On some, Thurber fescue (Festuca thurberi Vasey) predominates; on others, hairy goldaster (Chrysopsis villosa [Pursh] Nutt. ex DC) is the major species. These small parks are grazed extensively by cattle in summer.