Founded in 1907 as the Patapsco Forest Reserve, Patapsco Valley State Park is Maryland’s oldest state park. It is the site of some of Maryland’s earliest mills and factories, America’s first common-carrier railroad and the world’s first underwater hydroelectric plant. Catastrophic floods have damaged or destroyed many of the valley’s historic structures and sites. As you travel through the park, whether by foot, bicycle or car, keep an eye out for historic structures, sites and ruins. Wayside in