In the 1930s, McDowell Grove was a camp for the Civilian Conservation Corps — a work-relief program part of President Roosevelt’s New Deal legislation designed to combat Depression-era unemployment while conserving the nation’s natural resources. Workers constructed picnic areas, a plank bridge across the West Branch DuPage River, a boathouse, bridle path and a limestone dam on the West Branch DuPage River. The camp had six barracks, which provided housing for 200 workers. During World War II, the site served as a secret installation for developing radar technology. After Camp McDowell became a radar school in 1941, three additional barracks were added. The camp eventually served as a training site for Office of Strategic Services until 1944, and in 1946 the buildings were sold.

Starting in May 2013, the District and DuPage County Stormwater Management began a three-year project to restore a 3-mile stretch of the West DuPage River, including two miles in McDowell Grove Forest Preserve. In addition to improving flood control in the area, the project involved invasive species control and river restoration to improve habitat for fish and other aquatic species.