Rattlesnake Creek flows 23 miles from its headwaters in the southern Mission Mountains into the Missoula Valley, where it joins with the Clark Fork River. While the lower reaches of Rattlesnake Creek are confined by transportation corridors and urban development, its upper reaches in the Rattlesnake Wilderness and National Recreation Area are relatively pristine and support both fluvial and resident populations of native westslope cutthroat and bull trout.
In response to concerns about increasing development, riparian encroachment, and community sewage disposal in the lower Rattlesnake Creek Valley, the Rattlesnake Creek Watershed Group has developed a monthly water quality monitoring program to track chemical changes in the creek. To date, no consistent, long term water quality monitoring has been conducted on the creek, although periodic sampling efforts in the past have detected potential problems with nutrient levels. Starting a consistent water quality monitoring will help develop baseline values and allow interested parties to detect any degradative changes that occur as the valley population increases.
Water quality samples will be collected by volunteers from the Rattlesnake Watershed Group, under the supervision of the Missoula Valley Water Quality District and Missoula Valley Wastewater Treatment Plant. Sampling started in April 2008 and is occurring on a monthly basis.