The Knife River is a 23.9-mile-long (38.5 km)[2] river of northern Minnesota which drains a portion of Lake and Saint Louis counties into Lake Superior between Duluth and Two Harbors.

[3] The Knife River's name is an accurate preservation of its native Ojibwe name, Mookomani-Ziibi.

[4][5] Its original name was probably given on account of the long, sharp stones near the mouth of the river.

[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] The Knife River's watershed is undeveloped, with 72% forest, 16% wetland, and 6% grassland.