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(Page 2) MINE ID # OR PROSPECTING ID #: M-~nnn-i3~ INSPECTION DATE: 10-1F and 1n-7n-On INSPECTOR'S INITIALS: ~G- This inspection was conducted in response to a citizen complaint received from David L. Yoder on September 22, 2000 regarding pollution in the East Mancos River. The inspection began at a point along the River approximately 0.5 mi. upstream of the Yoder Ranch property. At this point along the river a significant accumulation of light-gray precipitate was observed within the active channel of the river. The precipitate has previously been identified as iron hydroxide by the USFS in a report on the same problem dated 01-04-1988. In an attempt to locate the source of the precipitate, the river was re-accessed approximately 7 miles upstream at a point about 1 mile below the headwater area in Rush Basin (please refer to attached map). In this portion of the river the channel bottom contained moderate iron sulfate deposits (brown staining) which may be associated with acid mine drainage emanating from old abandoned mine sites located farther upstream in the historic Rush Basin mining district. There was no evidence of the light-gray precipitate in this portion of the river. Snow cover prevented close inspection of the abandoned mine sites, however observations of the area from a distance revealed no evidence of recent mining or prospecting activity. At present there are no active permitted mining operations within the Rush Basin area. The entire portion of the river channel from the upstream starting point downstream to the conFluence with Gold Run Creek at the Red Arrow mining area was inspected on foot. Faint traces of the light-gray precipitate began to appear approximately midway between Rush Basin and the Red Arrow/Gold Dollar mine sites. This appears to indicate that the source of the light-gray precipitate is somewhere r m of the Red Arrow/Gold Dollar mining area, but not from any point source such as a mine site, natural acid seep, or tributary drainage. Accumulation of the precipitate increases gradually as the runoff proceeds downstream. The concentration of the precipitate observed within the portion of the channel passing below the Red Arrow mine area appeared to be essentially the same as that observed during several previous inspections of the Out West Mine and Mill, permit No. M-1981-184, which is located within a portion of the Red Arrow claim block. Although the upper portal of the permitted operation regularly discharges a few gallons per minute of water from the underground workings, pH measurements taken during previous inspections, and visual observations of the runoff, have not revealed any obvious water quality problems (no sulfide or iron hydroxide precipitate). Annual reports received from the operator and observations made during inspections indicate that no ore extraction, waste rock disposal, or milling has occurred at the permitted mining operation for several years. A small illegal prospecting operation (0.09 acres) occurring near the old Red Arrow mill building was investigated during the Fall of 1999, however the Division undertook appropriate enforcement action and the disturbance was reclaimed (except for revegetation) by the end of December, 1999. No evidence of release of contaminants into the river was observed during inspections of the illegal prospect site. The abandoned Gold Dollar mine site was also inspected, however no recent mining-related disturbances were observed. A minor amount (1-3 gpm) of mine water discharges from the collapsed mine opening, percolates through the old waste rock pile and then resurfaces into a small drainage approximately 700 feet above the river (please refer to attached map). However, it does not appear that this small amount of runoff is the cause of the light-gray precipitate observed in the East Mancos River channel. Only moderate iron-sulfate staining was observed in the runoff from the Gold Dollar Mine. Across the canyon from the Red Arrow mine is another small permitted mining operation (Twin Canyon Mine, M-1983-030). This operation has been inspected on several occasions and no mine water discharge has been observed. The Twin Canyon Mine is essentially a dry operation located several hundred feet above the East Mancos River channel, and it is highly unlikely that this operation is the cause of the precipitate observed in the river channel below. On 10/20/2000 the lower portion of the river situated between the Yoder Ranch property and the Red Arrow Mine was inspected on foot. The concentration of the light-gray precipitate increases gradually as the runoff proceeds downstream, but no identifiable point source for the precipitate was observed,