The upper portion of the Pere Marquette runs approximately 44 miles (71 km) from the forks of the Little South and Middle Branches downstream to highway M-37. In 1978, 66 miles (106 km) of the river was designated a National Scenic River. This section begins near Baldwin at the junction of the Little South and Middle Branches and continues until the river meets U.S. Highway 31 in Scottville.
This river's original native fish was the Grayling, but due to deforestation after the great Chicago Fire, they disappeared from the river. It was then stocked with rainbow trout in 1876. In 1884, the Baldwin River, a major tributary, became the first American river to ever be stocked with European brown trout fish, which were imported from Germany, and is why they are referred to by some as German Brown Trout.
Other animal species living along this river
^Matheny, Keith (25 November 2015). "New Zealand mudsnail Michigan's latest invasive species". Detroit Free Press. Gannett. Retrieved 27 November 2015. Sarah LeSage was on a floating trip with some girlfriends down the Pere Marquette River near Baldwin in Lake County last August, when the group stopped on the banks near Gleason's Landing to relax.... She took some samples, and the snails were later confirmed as the New Zealand mudsnail, the first time the invasive species had been found thriving in Michigan.