Castlerock Reservoir   Be the first to submit input for Castlerock Reservoir. If you have info on Castlerock Reservoir, Niobrara County, Wyoming please submit it here to improve this web site.          These outdoors activities are available near Castlerock Reservoir.   Public Lands Near Castlerock Reservoir: Agate Fossil Beds National Monument, Harrison - NE, 41 miles away Jewel Cave National Monument, Custer - SD, 67 miles away Wind Cave National Park, Hot Springs - SD, 67 miles away   Hotels Near Castlerock Reservoir: Americas Best Value Inn, Lusk, 15 miles away Best Western Pioneer, Lusk, 15 miles away Auto Inn Motel, Newcastle, 42 miles away Fountain Inn, Newcastle, 44 miles away