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2009 total-recoverable metal concentrations downstream from Granite was due to the increased panitioning of metals . to the paniculate phase and the resuspension of metal-laden sediment. Total-recoverable metal concentrations in the Arkansas River vary proponionally with suspended-sediment concentrations, which increase with increasing streamflow (Lewis and Edelmann, 1994). During the other three flow regimes, total-recoverable metal concentrations tended to peak at Empire Gulch, below the Leadville mining district, and decreased downstream. Stream velocities during snowmelt runoff typically are quite large and resuspend and transport substantial amounts of metal-laden sediment, whereas during the other three flow regimes, velocities are smaller and incapable of transporting substantial metal loads. Figure 4 near here. . During most flow regimes, dissolved Cd, Fe, Mn, and Zn concentrations were generally largest at Empire Gulch and decreased downstream (Figure 5) due to dilution by Lake Creek and increased partitioning to the particulate phase in the downstream direction. The largest concentrations of dissolved Cd, Fe, Mn, and Zn tended to occur during pre-snowmelt runoff. During pre-snowmelt runoff in April, streamflow begins to increase, as lower elevation snowmelt commences and begins to /lush the abandoned mines. mine dumps, and tailing piles of metal-enriched water. The volume of water that actually /lows into the river during the pre-snowmelt season is relatively small, but because flow in the river is also small, the impact on metal concentrations can be substantial. Dissolved Cu and Pb concentrations behave differently and tended to be largest during snowmelt runoff, with their maximum concentrations occurring below Empire Gulch. Dissolved Cu and Pb concentrations remained somewhat elevated downstream to about Nathrop or WellsviIIe (Figure 5). . 10