Photo courtesy of Cooke City Montana Museum The tailings impoundment extends outward from the mill and is likely encroaching on Soda Butte Creek. McLaren Gold Mine Mill near Cooke City, Montana, in 1946. Importantly, recent documented water quality exceedances are readily traced to two tributaries located outside the park boundary and not the former mill and tailings site.įigure 1. Results from this investigation indicate significant improvements in water quality in the vicinity of the reclaimed McLaren site and a reduction in the number of water quality exceedances documented at the Yellowstone National Park boundary. It also provides a summary of a basin-wide water quality inventory completed in 20 and documents benthic sediment chemistry post-reclamation. This investigation summarizes metal concentrations from a monitoring location downstream of the former McLaren site before and after the completion of reclamation work. The tailings at the McLaren site had leached metals into Soda Butte Creek for more than 80 years and posed an ongoing threat to Yellowstone National Park. This investigation followed the reclamation of the McLaren Mill and Tailings site, a long-sought-after objective by Yellowstone National Park, the State of Montana, and local environmental groups.
Soda Butte Creek is a tributary of the Lamar River whose water quality was impaired by historical mining activity near Cooke City, Montana. In 2015, National Park Service scientists teamed with the Montana Department of Environmental Quality to conduct a comprehensive characterization of water quality in Soda Butte Creek.