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' encountered in the sampling. Two of the species (thickspike wheatgrass and sheep fescue) accounted for more than three percent and less than 20 percent of the total cover ' by all species and a second species (Russian wildrye) accounted for more than 20 percent of the cover by all species. This satisfies, in part, requirements 2, 4 and 5 for cool season grass species. Nine forb species (eight perennial and one annual species) ' were encountered in the sampling. This satisfies requirement No.3, however none of the species accounted for as much as three percent of the cover by all species. Rocky Mountain beardtongue (Penstemon strictus) was the fikh-ranked species, and was the ' most frequently encountered forb (75 percent frequency). A complete list of all species observed on the site is presented in Table 13. From ' these results, it can be seen that numerous species occur throughout the reclaimed areas. ' Vegetation Cover Trends. The two reclaimed areas at the site have been sampled for vegetation cover for the last ten growing seasons. These data provide insight into the changes that have occurred. The most notable change over time in the 1 1984 area (Table 14) has been the increased amounts of big sagebrush which had a mean cover of approximately five percent in 1989 and has had a mean cover of approximately 20 percent for the past five growing seasons. The most notable change in the 1988 area ' (Table 15) has been the increase in the amount of Russian wildrye which has increased from less than one percent in 1989 to 17 percent in ]997 and ]998. ~___- ' CONCLUSIONS ' Aker fourteen and ten years of vegetation development, the sampling results show that that the revegetation of the mined lands at the Walden Coal Company site ' has been successful. Total vegetation cover, total ground cover and biomass production are all equal to or greater than 90 percent of the values obtained from reference areas located on the site. Shrub density values exceed the stipulated standard of 2000 t individuals per acre. The vegetation on the reclaimed areas supports numerous species in a variety of life form groups. ' LITERATURE CITED ' Colorado Division of Minerals and Geology. 1995. Guideline regarding selected coal mine bond release issues. Colorado Department of Natural Resources. ' Unpublished document. 28pp. Keammerer, W. R. 1997. Evaluation of revegetation success at the Walden Coal Company mine site. Unpublished report prepared for Walden Coal Company, Boulder, Colorado. 36 pp + map. ' -7-