Harrison Hills Park is a 500-acre (2.0 km2) county park in Allegheny County, Pennsylvania in the United States. It is a part of the county's 12,000-acre (49 km2) network of nine distinct parks. It is situated 24 miles (39 km) northeast of Pittsburgh in Harrison Township. The park features an overlook of the Allegheny River and offers walking, hiking, and bridle trails. The eastern trailhead of the 35.7-mile (57.5 km) Rachel Carson Trail is just north of the park's entrance. The trail traverses the park's eastern perimeter along the edge of a bluff overlooking the Allegheny River. It crosses Rachel Carson Run, via a wooden arch bridge above Rachel Carson Falls, which meanders below the Ox Roast grove.