Au Sable South Branch

About

The Mason Tract — 1954 Gift That Preserved the South Branch, Michigan. The paddling divides cleanly into two reaches. The upper run from Chase Bridge to Smith Bridge is narrow and wild; below Smith Bridge, the river widens into slower meanders on its way toward Roscommon. Across both, the South Branch runs riffles rather than heavy whitewater, and gauge 04135700 gives the reference: an average near 180 cubic feet per second, a historic flow of 162, and a working range of 100 to 400. The South Branch Canoe Livery rents canoes and kayaks on the reach.

Long before liveries and gauges, the river belonged to the Anishinaabe — the Ojibwe and Odawa — whose ancestral territory covered the Crawford and Roscommon county interior. The cold, spring-fed water sustained native brook trout and served as a primary travel corridor through the northern forest. The Little Traverse Bay Bands of Odawa Indians maintains cultural connections to the watershed today.

The river's defining wound came with the timber. From the 1830s through the 1920s, loggers worked the South Branch watershed, and a late-1800s boom stripped the banks of the trees that had kept the water cold and clear. Sawmills, logging drives, and downstream lumber operations ran the country until the resource gave out. The exhaustion of the old-growth stands around 1910, the start of state forestry conservation in 1915, and the establishment of state forests in the 1930s together brought large-scale logging to an end.

Recovery became the river's second story, and Grayling gave it a voice. The town is remembered as the birthplace of Trout Unlimited, where the cause of cold-water conservation found its early footing. Science followed conviction: the 1960s USGS Ausable River Basin Study, led by the Department of the Interior, produced the foundational hydrological assessment of the entire watershed, the South Branch included. In October 1984 the main Au Sable was designated a National Wild and Scenic River, and 23 miles of the South Branch were folded into that protection. The Michigan DNR's blue ribbon trout stream listing and the state's Natural River designation added further layers of standing.

The repair work has continued into the present. Through the 1990s and 2000s, Huron-Manistee National Forest stream restoration projects addressed the sedimentation left by more than a hundred years of logging, and from 1990 to 2020 the Anglers of the Au Sable worked alongside Trout Unlimited on the same legacy. Since 2010, the DNR and local watershed partnerships have layered on newer measures — streambank stabilization from 2015 to 2024, native fish restocking from 2017 to 2024, a nutrient-reduction strategy from 2018 to 2024, and broader water-quality improvements from 2020 to 2024. What logging nearly ruined, anglers and conservationists have spent more than a century restoring, and the South Branch now stands among the country's premier trout streams because of it.