county, northeastern Pennsylvania, U.S., bordered by New York state and New Jersey to the northeast and southeast, respectively (the Delaware River constituting the boundary), and Wallenpaupack Creek and Lake Wallenpaupack to the west. It consists of a hilly region on the eastern side of the Allegheny Plateau. Among its waterways are the Lackawaxen River, Shohola Lake, Pecks Pond, Shohola Creek, and Bush Kill. Parklands include Delaware State Forest, Delaware Water Gap National Recreation Area, Delaware National Scenic River, and Promised Land State Park, which is located on Promised Land Lake.

Milford, the county seat, was settled in 1733. The castlelike estate of Grey Towers belonged to Gifford Pinchot (Pinchot, Gifford), pioneer of forestry management and governor of Pennsylvania, who founded the Yale Summer School of Forestry at Milford. The county was formed in 1814 and named for U.S. Army officer and explorer Zebulon Montgomery Pike (Pike, Zebulon Montgomery). In 1848 engineer John Augustus Roebling (Roebling, John Augustus) completed a suspension aqueduct that is the oldest extant wire suspension bridge in the nation.

Tourism is the primary industry. Pike county is one of seven completely rural counties in Pennsylvania. Area 547 square miles (1,417 square km). Pop. (2000) 46,302; (2007 est.) 58,633.