St. Croix Watershed Research Station Blog:
“Lake of the Woods is the vast body of water that makes up most of the spur on Minnesota’s northern border. Sprawled across the U.S.-Canada border, it is 70 miles north-south and 60 miles east-west, contains more than 14,552 islands, and boasts 65,000 miles of shoreline. It is the size of Rhode Island and a good candidate as the “sixth Great Lake.”
Like Lake Erie and other Great Lakes, Lake of the Woods is also plagued by harmful algal blooms. Even after nutrient pollution was reduced, Lake of the Woods seems to keep getting greener.
Enormous amounts of waste discharged from paper mills on the Rainy River poured into the lake for decades, carrying phosphorus, which fed the algae. City wastewater also went straight into the river. After the Clean Water Act was passed in 1972, the waste discharges were significantly lowered and the overall cleanliness of the water entering the lake was improved.”
