The Ontonagon River's principal tributaries are its West, South, Middle and East branches, all of which flow in part through the
Ottawa National Forest:[6]
The West Branch Ontonagon River[7] is entirely contained in
Ontonagon County. It begins at the outlet of
Lake Gogebic near the community of
Bergland and flows generally east-northeastwardly for approximately 34.5 miles (55.5 km),[8] collecting the South Branch and passing through a dam which forms the Victoria Reservoir.[4][6]
The South Branch Ontonagon River[9] is formed in southwestern Ontonagon County by the confluence of the short Tenmile Creek and the Cisco Branch Ontonagon River. The Cisco Branch starts in Cisco Lake in eastern
Gogebic County and flows generally north-northeastwardly for 32.7 miles (52.7 km)[8] to the South Branch,[10] which then flows northwardly for 33.3 miles (53.6 km),[8] passing the community of
Ewen, to join the West Branch.[6]
The Middle Branch Ontonagon River,[11] 70.7 miles (113.8 km) long,[8] issues from Crooked Lake in eastern Gogebic County and initially flows eastwardly, passing the community of
Watersmeet. After collecting the
Tamarack River, the Middle Branch turns northwardly into Ontonagon County, where it collects the
Baltimore River and joins the East Branch.[6]
The East Branch Ontonagon River,[12] 59.3 miles (95.4 km) long,[8] issues from Jingle Lake in northern
Iron County and flows generally northwestwardly through
Houghton County into Ontonagon County, where it joins the Middle Branch.[6]
Below the confluence of its various branches, the Ontonagon River flows generally north-northwestwardly for 24.7 miles (39.7 km)[8] in Ontonagon County to the village of
Ontonagon, where it flows into
Lake Superior.[6]
National Wild and Scenic River designation
On March 3, 1992, the following reaches of the Ontonagon's upper tributaries were collectively designated the Ontonagon National Wild and Scenic River: The upper courses of the East and Middle branches in the
Ottawa National Forest; the Cisco Branch in its entirety; and approximately the middle section of the West Branch, from Cascade Falls to the Victoria Reservoir.[5][6]
^
abThe American Rivers Outstanding Rivers List, Second Edition, May 1991. Compiled and edited by Matthew H. Huntington and John D. Echeverria. Washington, DC: American Rivers, Inc.