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La Plata Mine is located in northwestern New Mexico. The pre-mine landscape is characterized by rough broken topography with moderately steep to steep scarp and dip-slopes. This area of New Mexico is primary winter range for ungulates migrating from southern Colorado. The majority of the pre-mine lease area consisted of south facing dip-slopes. In designing the post-mine landscape the mine was faced with 35% spoil swell. This results in potentially creating longer and steeper slopes than the existing pre-mine slopes. The design also has to consider the requirement that post-mine landscapes have soil-loss rates less than or equal to pre-mining conditions. The final surface configuration (FSC) was designed with the primary purpose of promoting biodiversity and maintaining low soil-loss. Special land features such as talus slopes, scalloped slopes, rock-piles, and water harvesting features were included to meet these objectives. In addition, variable soil substrates, including suitable spoil materials, and coarse textured topsoil materials were targeted for steep slopes to minimize soil loss and to promote shrub establishment. Finer textured topsoil materials were targeted for lowlands and valleys to promote establishment of grasses. Stability of the final surface design was validated using the RUSLE model. Welldesigned reclamation plans can enhance post-mine biodiversity through the use of variable landscapes and soil substrata.

Abstract. Biodiversity has increasingly become an important issue in determining the success of reclaimed minelands. The post-mine land-use of La Plata Mine is wildlife habitat, primarily for ungulates and small mammals. A reclamation plan was developed to promote biodiversity of reclaimed lands through the use of variable soil substrates, landscape features, and targeted seed mixes. A GIS was used to delineate the post-mine final surface contour into eight slope classes and eight aspect classes. The class information was used to develop four reclamation land types: I. Upland shrub -north aspects, 2. Upland shrub -south aspects, 3. Grassland, and 4. Drainage. These land types correspond to four reclamation vegetation types. Suitable spoil materials and coarse textured topsoil materials were targeted for use on strongly sloping areas to minimize soil loss. Finer textured topsoil materials were targeted for the grassland and drainage types. The replacement depth of topsoil and topsoil substitute materials was varied for the reclamation vegetation types. Pre-mine vegetation inventories were used to develop unique seed mixes ' specific to physical habitat conditions exhibited by each land-type. Research conducted at La Plata Mine found that topsoil replacement thickness less than 15 cm promotes shrub establishment and topsoil thickness greater than 30 cm promotes native grass species. Therefore, areas designated for shrub communities will receive an average of IO cm of topsoil or topsoil substitute material and the areas designated for grassland and drainage type communities will receive a minimum of 40 cm of topsoil.Additional