Pennsylvania Route 321 (PA 321) is a 43.8-mile-long (70.5 km) state highway located in Elk and McKean counties in the U.S. state of Pennsylvania, maintained by the Pennsylvania Department of Transportation (PennDOT). The southern terminus is at U.S. Route 219 (US 219) in the community of Wilcox. The northern terminus is at PA 346 within the Allegheny National Forest. PA 321 heads northwest from Wilcox through rural areas to the borough of Kane, where it forms a brief concurrency with US 6. North of here, the route heads through the national forest and runs along the shore of the Allegheny Reservoir. PA 321 runs east briefly with PA 59 before winding north through more forest to its northern terminus. A portion of the route along the Allegheny Reservoir is designated as the Longhouse Nation