Northern Prairie Wildlife Research Center
The study areas had been chosen for other studies, designed to develop and test methods of monitoring environmental quality in the Prairie Pothole Region. These studies, for U.S. Environmental Protection Agency's (EPA) Environmental Monitoring and Assessment Program, were conducted jointly by EPA, the Northern Prairie Science Center, and other cooperators. The sample units were 44 hexagons, each 40 ha in size.
Within each hexagon, we selected a route consisting of secondary roads or trails. We endeavored to sample from throughout the hexagon. Stations were located at half-mile intervals along the route, usually along section lines or half-section lines. We tried to make routes continuous and at least 10 miles long, but limited road networks in some areas precluded meeting these criteria. Actual route lengths ranged from 7 to 14 miles. Because of heavy precipitation preceding and during the survey period, roads were frequently washed out, which necessitated altering routes to reach certain stations.