Patapsco Valley State Park spans more than 16,000 acres along 32 miles of the Patapsco River. Visitors can hike on the more than 170 miles of trails; fish, swim or canoe along the Patapsco River; picnic in an open area, or one of the many pavilions; or take in the scenery from atop a horse or a mountain bike. The park is more than 100 years old.