The Red River of the North - Grand Marais Creek watershed is part of the Red River Basin in northwestern Minnesota and southeastern North Dakota. The watershed occurs in the Glacial Lake Agassiz Plain Level III ecoregion. The Red River begins its course just below Wahpeton, North Dakota, at an elevation of 943 feet. The river descends a mere 172 feet over the 140+ mile journey between its origin and the northern boundary of the watershed north of Oslo, Minnesota. The watershed covers 298,264 acres.
The Red River has a poorly defined floodplain and low gradient that combine with extensive drainage, widespread conversion of tallgrass prairie to farmland, and urban/suburban development to leave the basin subject to frequent floods that affect urban and rural infrastructure and agricultural production. The main resource concerns in the watershed are wind and water erosion, nutrient management, wetland management, surface water quality, flood damage reduction, and wildlife habitat. Many of the resource concerns relate directly to flooding and increased sediment and pollutant loading of surface waters. Above-normal amounts of precipitation in the late fall of the year or from May to October lead to high levels of soil moisture, periodically producing the snow-melt and summer floods that are known to affect the region.
Over 99% of the land in the watershed is held by private landowners. Land use within the watershed is largely agricultural, accounting for nearly 92% of the overall watershed acres. Development pressure is moderate in the basin, with occasional farms being parceled out for development, recreation, or country homes.