A wetland with the prairie in the background, lots of swans and geese swimming in the water.

The Refuge includes over 6,000 acres of wetland habitat.  The once seasonally flooded wetland basin was transformed to a semi-permanent wetland basin in the early 1960's and is now returning to a seasonal basin with a variety of wetland flooding and drying regimes.

When the Refuge was established in 1929, the flooding of the wetland basin fluctuated with the amount of natural runoff received. This included large shifts in the duration and depth of flooding in the wetland basin from several hundred acres to over 6,000 acres. These shifts corresponded to the wet and dry cycle of the Northern Great Plains prairies. 




Concern with the fluctuations in flooding and extended dry periods prompted members of the Cascade County Wildlife Association to secure Congressional funding to transform the marsh into a consistently wet environment. From 1958-1962, a pump station, pipeline, and multiple impoundments with water-control structures were constructed to bring irrigation return flow water from Muddy Creek about 15 miles west of the Refuge. This management regime was implemented with some modifications until 2012.






The consistent flooding regime resulted in unexpected consequences including: selenium toxicity, domination of single vegetative species, establishment and aggressive expansion of non-native vegetative species, and loss of production. The Service in cooperation with local interest groups and Montana Fish, Wildlife, and Parks recently developed an alternative management plan that will restore the wetland health and strive to provide reliable fall waterfowl hunting opportunity. More information about this management direction can be found in the Final Comprehensive Conservation Management Plan for the Benton Lake NWR Complex and the Habitat Management Plan that will be completed by 2014.

More information about the Structured Decision Making Process that the Service participated in with Montana Fish, Wildlife, and Parks can be found at: http://www.fws.gov/mountain-prairie/planning/ccp/mt/bnl/documents/bnl_nwr_structured_decision_report.pdf