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• brush, forbs, and grasses. Where soils are rich in the higher elevations and northern slopes, there are <br />stands of ponderosa pine and oak brush. <br />The northern portion of the mesa where the mine is located drains into Lumsden Creek, an intermittent <br />drainage that flows in the spring and after large precipitation events. Lumsden Creek flows into the <br />Dolores River north of Gateway as shown on Map G-1. The elevation drops to 4,550 feet at the <br />Dolores River. Lumsden Creek is fed by three small springs: DP Spring, PR Spring, and Lumsden <br />Spring (see Map G-1). These springs occur at or near where sandstone aquifers intersect the Lumsden <br />Fault (see Map G-2), which bisects the canyon. <br />The closest water wells to the mine are the Shallow and Deep Cherokee Wells located about 2,000 feet <br />east to southeast of the Whirlwind portal. These wells are both completed in the upper Brushy Basin <br />Member of the Morrison Formation, which is above the Salt Wash Member where the mine workings <br />are located. The Cherokee Wells, which produce only small amounts of water, are currently capped <br />and not in use. They were used historically as water sources for the Cherokee Mine Camp. There is <br />also an agricultural well (BLM Well) located on top of the mesa about 1 mile due west of the <br />Whirlwind portal on the Utah side of the state line. This well is completed in the Burro Canyo <br />Formation, which is also located above the mine workings. It is used by a local rancher for w <br />livestock. The closest downstream water well to the mine within the Lumsden Creek Watersh <br />Lonie Ranch Well located about 5 miles from the mine area near the Dolores River. This wel <br />probably completed in the river alluvium. <br />3. Regional Geology <br />n <br />atering <br />ed is the <br />1 is <br />The Whirlwind Mine lies in the central and east-central part of the Colorado Plateau in Utah and <br />Colorado as shown on Figure G1. The Plateau's basement rocks are mostly Proterozoic metamorphics <br />and igneous intrusions. The area was relatively stable throughout the Paleozoic and Mesozoic Eras <br />with minor uplifts, subsidence, and tilting resulting in fairly flat-lying sedimentary rocks ranging from <br />evaporites, limestones, and marine clastic sediments, through eolian sandstones, to detritus of fluvial <br />systems. The Uncompahgre Uplift, seven miles northeast of the Whirlwind claims, was active during <br />• the late Paleozoic so that Pennsylvanian through early Jurassic sedimentary rocks wedge out against <br />Whirlwind Mine 07 (rev. April 08) G-2 <br />