Clark Reservation State Park is a state park in Onondaga County, New York. The park is in Jamesville, NY, in the Town of DeWitt, south of Syracuse. It was the site of a large waterfall formed by melting glacial ice at the end of the last Ice Age; the plunge basin at the base of the old falls is now a small meromictic lake.

Clark Reservation is also noted for its many ferns; it harbors the largest population in the U.S. of American hart's tongue, which is so rare that it was declared endangered in the U.S. in 1989.

Aside from the stunning geological significance of the park, an equally impressive and diverse species of plant life make this park literally a wild botanical garden. Hundreds of flowering plants, 80 species of trees, 100 types of moss, and, most notably, 26 species of ferns are all observable along the nearly six miles of interconnected loop trails.

The park has multiple connected/looping hiking trails ranging from easy to moderate. They include the Mildred Faust trail, Cliff trail, Long and Long Extension trails, Pulpit Rock Trail, and Saddle Back trail. There around about 6 miles of hiking trails.