Knife River (Lake Superior)

The main branch of the Knife River flows 23.9 miles (38.5 km) from source to mouth,^[2] flowing parallel to the shoreline from the direction of Two Harbors.^[1] It has four or five major tributaries.^[1] Its watershed is 84.3 square miles (218 km²), and contains 181.1 miles (291.5 km) of streams.^[7] Since data began being collected in 1974, its mean annual daily water discharge has been calculated as 90.3 cubic feet per second (2.56 m³/s).^[1] There is concern over the river's water quality due to suspended sediment, and it was placed on the state's impaired waters list in 1998.^[8] A 2008 study found that about sixty percent of the sediment came from erosion of the streambanks, and about thirty from erosion of the river's bluffs.^[1]

The Knife River's watershed is undeveloped, with 72% forest, 16% wetland, and 6% grassland.^[7] 5% is used for agricultural purposes, and the remaining 1% is the unincorporated community of Knife River, Minnesota, located at the river's mouth.^[7]

• List of rivers of Minnesota