Beaver activity, particularly dams, have been shown to alter stream and riparian vegetation characteristics. The presence of dams tends to increases the ability of a stream to connect with its floodplain. The absence of beaver dams may lead to incision of the stream. The University of Montana Western Hydrology class collected data on beaver activity and wetlands on Alkali Creek, a tributary of the East Fork of Blacktail Creek in Southwest Montana. What we found was a variety and abundance of beaver sign including dams, lodges, and other evidence. Wetlands tended to exist in areas of high beaver activity and were less abundant in stream sections with less beaver activity. General observations indicated that the beaver activity on Alkali Creek changed sediment flow, water velocity and morphological stream characteristics. The data will be used as part of an ongoing beaver monitoring effort for Montana Fish Wildlife and Parks.