Jay Cooke State Park is a state park of Minnesota, United States, protecting the lower reaches of the St. Louis River. The park is located about 10 miles (16 km) southwest of Duluth and is one of the ten most visited state parks in Minnesota. The western half of the park contains part of a rocky, 13-mile (21 km) gorge. This was a major barrier to Native Americans and early Europeans traveling by canoe, which they bypassed with the challenging Grand Portage of the St. Louis River. The river was a vital link connecting the Mississippi waterways to the west with the Great Lakes to the east.
Today Minnesota State Highway 210 runs through Jay Cooke State Park. The 9 miles (14 km) of the route between Carlton and Highway 23—which include the park—are designated the Rushing Rapids Parkway, a state scenic byway.
The park is named for Pennsylvania financier Jay Cooke, who had developed a nearby power plant, which is still in use. The Grand Portage trail and three districts of 1930s park structures are listed on the National Register of Historic Places.