Altnow Gap Reservoir   Be the first to submit input for Altnow Gap Reservoir. If you have info on Altnow Gap Reservoir, Harney County, Oregon please submit it here to improve this web site.          These outdoors activities are available near Altnow Gap Reservoir.   Lakes Near Altnow Gap Reservoir: Warm Springs Reservoir, Malheur County, 9 miles away   Public Lands Near Altnow Gap Reservoir: Malheur National Forest, Oregon, 26 miles away Unity Lake State Park, Oregon, 38 miles away