Home Allegheny Land Trust/Dead Man's Hollow Website Email Dead Man's Hollow is a 450-acre Allegheny Land Trust woodland rich in history, mystery, and ecological wonder! Located along the Great Allegheny Passage, the greenspace is popular for hiking and biking. Allegheny Land Trust/Dead Man's Hollow 416 Thorn St. Sewickley, Pennsylvania 15143 (412) 741-2750