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due to the dilution of alluvial ground water by North Fork River water at this well. Except for areas in the Minnesota Creek Drainage, the alluvium along the lower reaches of tributaries to the North Fork is predominantly thin and confined to discontinuous narrow bands along the stream courses. The deeply incised channels of these tributaries restrict the width of the alluvium, while the stream gradient and the presence of resistant sandstone in the stream channels limit the thickness and downstream extent of the alluvium. Two mines in the region draw water from the alluvium of tributaries to the North Fork, the Blue Ribbon Mine draws from the alluvium of Hubbard Creek and the Orchard Valley Mine draws water from the alluvium of Stevens Gulch. Pumping tests conducted by Colorado Westmoreland Incorporated at the Orchard Valley Mine indicate that the Stevens Gulch alluvium could support a pumping rate of 28 gpm. The Bear Mine and Terror Creek Loadout use some water drawn from wells completed in the alluvium along the North Fork of the Gunnison River. Water quality analysis for the Stevens Gulch well water indicates good quality water, with none of the parameters exceeding the recommended drinking water standards. The water quality for the Hubbard Creek well water is fair to poor and contains total dissolved solids and sodium levels which at times exceed secondary water quality standards for drinking water. Occurrences of ground water have been noted in the Mesa Verde Formation from information obtained from drilling, experience in the mines, and from-the presence of springs and seeps in the region. This information also indicates that the only potential regional bedrock aquifer in the general area is the laterally continuous Rollins sandstone. The laterally discontinuous lenticular sandstones within the Upper Mesa Verde Formation support only localized ground water flows. Of 112 exploration drill holes at the Mt. Gunnison Mine that were drilled prior to the mine opening, only three of the holes produced water from the F seam at a rate of 3 gpm or less. Three other holes in the Barren member had rates of about 0.75 gpm. Recharge to the Rollins sandstone occurs along outcrops, along subcrops beneath stream alluvium and in the channels of the North Fork and its tributaries. However, due to the steepness of the topography in the outcrop areas (i.e, sandstones are cliff formers) and the narrowness of the stream valleys, the Rollins sandstone receives little recharge, except in the area under the North Fork of the Gunnison River and its associated alluvial deposits. Some recharge to the Rollins sandstone may come indirectly from the percolation of snowmelt and precipitation downward through faults and fractures. Drill holes which penetrated the Rollins sandstone near the 36