Migrant Indian tribes led by Chief Okemos called this area "Big Rocks" and came here in early spring to tap the sugar maples. Later, the beauty of the ledges and woods attracted the Grand Ledge Spiritualist Camp Association, which in 1894 established a summer campground and erected the large pavilion that still stands. Thousands of spiritualists came here for summer encampments until the turn of the century. In 1919, the City of Grand Ledge bought the property and named it Riverside Park. The pavilion was used for dances, roller skating, and basketball, and during World War II it housed a factory. The park's name honors Grand Ledge native Governor Frank D. Fitzgerald, who died in office in 1939. The pavilion was refurbished as a summer theater by the Grand Ledge Improvement Association in 1955.