The Dowagiac River watershed is the area whose snow and rain drain into the Dowagiac River through surface runoff or groundwater infiltration, covering about 287 square miles, or 181,347 acres, with a perimeter of 108 miles across Berrien, Cass, and Van Buren counties and including 16 townships, two cities, two villages, 23 lakes, and major tributaries such as Dowagiac Creek, Pokagon Creek, Peavine Creek, McKinzie (Kinzie) Creek, Silver Creek, and Lake of the Woods Drain. Today it is dominated by agriculture, with some upland and lowland forests, isolated prairies, and wetlands that help maintain the river’s unique hydrology. The Dowagiac River is unusual for a southern Michigan river of its size because it is fed mostly by groundwater, producing cold, stable flows that support a cold-water fishery and give it the potential to be one of the finest trout rivers in the Midwest. After the Ice Age, a six- to eight-mile-wide lake known as Lake Dowagiake formed from melting glaciers and stretched 120 miles from Grand Rapids to South Bend, with the City of Dowagiac as its deepest area, before draining south and diminishing until only two small lakes on the University of Notre Dame campus remained from the glacial lake. Dowagiac Creek flows into the Dowagiac River, which then flows into the St. Joseph River and on into Lake Michigan. Along Dowagiac Creek, lunker structures have been installed to provide in-stream cover for fish and improve trout habitat. Similar to wooden pallets and placed adjacent and parallel to a stream bank, these structures stabilize banks, prevent erosion, and, by narrowing the channel on the outside bend, create deeper pools that improve fish habitat. Trees and shrubs beside the stream provide similar benefits, and although lunker structures are expensive to build from hardwood planks such as white oak, they require little maintenance once installed.