St. Mary's Run Watershed is a small watershed located in northern Frederick County, MD. The watershed contains a mix of land uses including agriculture, forest, and residential and is bisected by a major highway.

Biologists and Environmental Scientists from Mount St. Mary's University monitor the health of this watershed and study the impacts of land use practices on the local streams.

In this photo students in Environmental Science class are installing acid deposition collectors on Mount St. Mary's University campus.