The Flat river is a tributary to the Grand river and emerges from a six a six lakes sytem in Montcalm county. Known for the bass and rather large carp that call it home, the Flat river runs through the town of Lowell, just east of Grand Rapids. Smallmouth bass are the primary quarry, from early spring streamer fishing through summer fly hatches that will bring bass to the surface for flies at dusk. Best fished early spring through mid-summer, the Flat flows from a 30-40 yard wide river with good structure and current flow, into a marsh before it's directed through a dam in Lowell and shortly after, feeds directly into the Grand river. Can be waded in many spots, best accessed from a boat near the headwaters of the marsh.