Lake Assessment Program - Lake of the Woods Trophic Status Report 2005 Update, Lake of the Woods County

Lake of the Woods is located on the U.S. and Canadian border between Minnesota, Ontario and Manitoba (Figure 1). It is the largest lake in Minnesota, although only about one third of the lake's 950,400 acres are within the state. Rainy River is the largest tributary to the Lake, contributing over 70% of the inflow (MN DNR and OMNR, 1998). Water from the lake eventually makes its way to Hudson Bay, via the Winnipeg River at Kenora, Ontario. Since land use affects water quality, it has proven helpful to divide the state into regions where land use and water resources are similar. Minnesota is divided into seven regions, referred to as ecoregions, as defined by soils, land surface form, natural vegetation and current land use. Data gathered from representative, minimally-impacted (reference) lakes within each ecoregion serve as a basis for comparing the water quality and characteristics of other lakes. Lake of the Woods is located in the Northern Minnesota Wetlands ecoregion, however the majority of its Minnesota watershed is located in the Northern Lakes and Forests (NLF) ecoregion (Figure 2).