Long Hollow Reservoir   Be the first to submit input for Long Hollow Reservoir. If you have info on Long Hollow Reservoir, Steens Mountains, Harney County, Oregon please submit it here to improve this web site.          These outdoors activities are available near Long Hollow Reservoir.   Campgrounds Near Long Hollow Reservoir: Blitzen Crossing Campground, Harney County, 15 miles away   Hiking Trails Near Long Hollow Reservoir: The Beef Trail, Harney County, 3 miles away       5 hiking miles, 644 feet elevation difference