Double wedge research plots are used to simultaneously evaluate the effects of cover soil depth and suitable spoil depth on reclamation. A double wedge was constructed and seeded in the fall of 1993 at a coal mine in northwestern New Mexico. The purpose was to determine "optimal" depths of cover soil and suitable spoil. Depth of cover soil ranged from 0 to 90 cm and depth of suitable spoil ranged from 0 to 120 cm. Sample points were established at 49 permanent locations evenly spaced throughout the plot. Vegetation sampling events were conducted in November 2003 and June of 2004 to determine vegetative cover, production, shrub density, and species diversity. Cover soil and suitable spoil depths were used to evaluate the response of cover, production, and diversity. Total cover and production increased with cover soil depth. Rabbitbrush density decreased with cover soil depth, whereas winterfat density increased with cover soil depth. The greatest species diversity occurred at cover soil depth between 25 and 65 cm. None of the vegetation parameters were affected by suitable spoil depth Additional

Iron mining in Michigan's Upper Peninsula has unavoidably impacted regulated wetlands. State and federal laws require these wetland impacts be mitigated by the creation or restoration of compensatory wetlands. Integrating wetland creation with tailings basin reclamation provided the necessary wetland acreage for regulatory compliance. The properties of the tailings and the design of the basins provided not only a suitable medium and location for wetland creation, but also presented substantial challenges. The creation of new wetlands required manipulation of the water levels within the basins and careful wetland design. Michigan Department of Environmental Quality permits required creating emergent, scrub/shrub, and forested wetland communities on neutral tailings. Numerous planting and seeding techniques were used to establish the different plant communities. These techniques included dormant seeding, drill seeding, aerial seeding, and transplanting wetland vegetation. Cover crops of Japanese millet (Echinochloa crusgalli) and red-top grass (Argrostis alba) were used in conjunction with hay mulch minimize erosion and sequester wind blown seeds from the surrounding native areas. Forested wetlands were established by transplanting wetland tree species at specific tree densities to compensate for expected mortality. The established wetland communities were monitored annually for a period five years to document the successful development of vegetation, hydrology, and wildlife in accordance with reclamation success criteria.

Molycorp, Inc. operates a molybdenum mine and associated tailings facility, near the Village of Questa, New Mexico. Neutral tailings are pumped 5.6 km from the mine to the Questa Tailings Facility where interim reclamation activities have been conducted for over 30 years. Four interim reclamation areas of the tailings facility, widely ranging in age, were evaluated for the effect of cover soil depth on plant communities. Sampling of various plant community components was conducted along random transects. The plant community components include; plant cover, shrub density, and species diversity. The evaluations suggested that depth of cover soil has little influence on the plant community components.Additional Key Words: tailings basins revegetation, cover depth, and reclamation.