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all vegetative cover) provided by grass species was 49.4% in 2008 and 73.1 % in 2009. Perennial <br />cool season grasses dominated the grasses, with the most abundant species being thickspike <br />wheatgrass and intermediate wheatgrass. Additional significant herbaceous cover was provided by <br />western wheatgrass and smooth brome. Forbs comprised relative cover of 49.9% in 2008 and 18.3% <br />in 2009. Forbs were cool season perennial, biennial, and annual species, dominated by yellow <br />sweetclover, various mustards, and some weeds. The most abundant weed species (Musk thistle, <br />Canada thistle, bindweed, and mullein) together comprised 2.9% of relative cover in 2008 and 7.1 % <br />of relative cover in 2009. Twelve species of desirable forbs were identified in the 2009 samples. <br />Two woody shrub species, Rubber Rabbitbrush and Wood's rose, appeared in the sample data with <br />Rubber Rabbitbrush comprising 7.5% relative cover in 2008 and 0.7% relative cover in 2009. <br />Although the vegetative sample data fell short of the approved revegetation success criterion of 70% <br />live cover, the data compare favorably with the following technical standards for cover and species <br />diversity that were adopted by the Division at a pre-law coal mine site, the Blue Flame Mine, located <br />approximately nine miles to the southwest. The Blue Flame site is similar to the Coal Gulch site in <br />terms of pre-law disturbance, climatic conditions, soil erodibility characteristics, and postmining <br />land use. <br />Cover and Diversity Technical Standards at Blue Flame Mine <br />Herbaceous cover: 30% <br />Species diversity: 2 cools season grasses <br />2 warm season grasses <br />2 forbs <br />2 shrubs <br />No single species shall compose more than 40% <br />or less than 3% relative cover <br />The sample data from the Coal Gulch Mine indicate the reclaimed areas have a diverse assemblage <br />of grasses and forbs, with a woody shrub population that is beginning to develop. The grasses, forbs, <br />and shrubs on the Coal Gulch site are a self-sustaining mix of vegetation that provides long-term <br />erosional stability. Open grass land on the disturbed area of the site is surrounded by undisturbed <br />valley slopes that are covered by woody shrubs which provide areas of wildlife cover and forage. <br />Erosion Control and Sediment Yield <br />The vegetative cover on reclaimed areas appears to be preventing most rill and gully formation. <br />During the bond release inspection and recent inspections, hillslopes showed significant down- <br />cutting from concentrated flow only on the waste pile. No delta or sediment fans have been found on <br />the site during recent inspections, with the exception of the sediment fan near the center of the site <br />that comes from the adjacent Arness McGriffin site. <br />Using the observed cover values in the Universal Soil Loss Equation, the calculated soil loss rate is <br />6