Finch Creek primarily flows into the lower Grass River, not far upstream from Clam Lake, although a divergent channel near its mouth flows directly into Clam Lake. The stream system has two tributaries, only one of which is named (Crow Creek). The most distant of these tributaries originates about 6.5 miles upstream of the stream mouth.
Finch Creek originates in a swamp between high moraines, not far from the headwaters of Spencer Creek (which flows into Torch Lake). The last half mile of the stream flows through a swampy area within the Grass River Natural Area. There is no other public land along the stream. The greatest elevation of the Creek’s headwaters is 1,034 feet. The stream drops 443 feet in elevation, for an average stream gradient of about 68 feet per mile. The stream system is crossed by Alden Highway (C-618), and Finch Creek, Elder, and Bebb Roads. At Alden Highway, the stream is about 20 feet wide and one to three feet deep, with a sand bottom. There are quite a few logs and other woody debris in the stream. The stream has many stable undercut banks. Watercress grows abundantly along the edges, and underwater rocks and logs are covered with aquatic moss. The stream water is unstained and clear, except when road surface runoff from Finch Road causes cloudiness. Thermal characteristics of the stream indicate that it has high levels of ground water input. The stream is located in Helena and Custer Townships (Antrim County). Finch Creek is designated as a trout stream by the MDNR.
An environmental survey conducted by the Grass River Natural Area in 1984 found that the mean monthly stream temperature never rises above 68 degrees and that fast, turbulent flow conditions generally prevail. Brook, brown, and rainbow trout; and slimy sculpins were found to dominate the upper reaches of the Creek, with mudminnows being found in some backwater areas. Abundant and diverse invertebrate fauna were documented, possibly due to the presence of abundant woody debris. Grayling were planted in Finch Creek in 1936 in a failed attempt to reintroduce the species to Michigan.