Located in the southwest portion of the Lower Peninsula of Michigan and the northern portion of Indiana, the St. Joseph River Watershed spans the Michigan-Indiana border and empties into Lake Michigan at St. Joseph, Michigan. The watershed includes 3,742 river miles and drains 4,685 square miles from 15 counties (Berrien, Branch, Calhoun, Cass, Hillsdale, Kalamazoo, St. Joseph and Van Buren in Michigan; De Kalb, Elkhart, Kosciusko, Lagrange, Noble, St. Joseph and Steuben in Indiana). The river flows near the Kalamazoo-Battle Creek area in Michigan and through the Elkhart-Goshen and the South Bend metropolitan areas in Indiana. According to the 2000 U.S. Census, 1,524,941 people live in the 15 counties of the watershed with 53.6% living in Michigan. The most populated county is St. Joseph, Indiana. The watershed is largely agricultural. More than 50% of the riparian habitat is agricultural/urban, while 25-50% remains forested.
To support the issues which concern the welfare of the St. Joseph River:
The conservation of the water supply in the river and its watershed, the maintenance of the water quality of the river, evaluation of hydrological data of the river and its tributaries so that decisions and actions of the corporation may be conducive to the betterment of the river and to operate exclusively for education, historical, charitable, and scientific purposes.