Blairstown, in Blairstown Township, is located in
Warren County, in the
Skylands Region, and is part of the
Newark, New Jersey metropolitan area. Blairstown is situated on the Paulinskill Valley Trail, between Paulina, one mile to the east, and Jacksonburg, two miles to the west. It is surrounded by several lakes. Three miles west is Worthington State Forest, Yards Creek Reserve, and the Delaware Water Gap.