The National Park Service (NPS) Grant-Kohrs Ranch National Historic Site commemorates the western frontier cattle era and is located in southwestern Montana, adjacent to the town of Deer Lodge. The GRKO is unique among National Park Service Units because it has the distinction of being the only NPS unit to be included on the National Priority List for Superfund cleanup.

The objective of the study is to provide high-accuracy real-time continuous estimates of metallic contaminant concentrations (MCCs) to quantify the effects of GRKO remediation activities on constituent transport in the Clark Fork as it flows through the GRKO property. Improved estimates of concentrations and loads will help the GRKO monitor and evaluate effects of the remediation activities.