It rises in northern Lane County, approximately northeast of Springfield. It flows generally southwest and enters the McKenzie from the north on the north side of Springfield. The river's valley is known as the Mohawk Valley.
The Mohawk River was probably given its name by Jacob C. Spores in 1849. Spores was a native of the Mohawk River region of New York, and the Oregon river's valley reminded him of the Mohawk Valley in his home state. In turn, the Oregon river gave its name to the Mohawk River band of KalapuyanNative Americans who inhabited the river valley in the 19th century. They are not related to the Mohawk tribe in the eastern United States.