formed by its East and South Forks at 614730N, 1473015W, flows SW to the Knik Arm Cook Inlet, 9.5 mi. SW of Palmer, Cook Inlet Low.
Name derived from the Russian term for the "copper river people" spelled Matanooski, Mednofski, Miduuski, Mednoviska, etc. It appears to be the same name used by the Russians for the Ahtena Indians on the Copper River, and may have originally been used in the 19th century to imply a route from Cook Inlet to the Copper River. The present spelling was used by U.S. Coast and Geodetic Survey (USC&GS) in 1897.