Dennis Reservoir   Be the first to submit input for Dennis Reservoir. If you have info on Dennis Reservoir, Crook County, Wyoming please submit it here to improve this web site.          These outdoors activities are available near Dennis Reservoir.   Public Lands Near Dennis Reservoir: Devils Tower National Monument, Devils Tower - WY, 53 miles away Jewel Cave National Monument, Custer - SD, 63 miles away Mount Rushmore National Memorial, Keystone - SD, 68 miles away   Hotels Near Dennis Reservoir: AmericInn Belle Fourche, Belle Fourche, 18 miles away Super 8 Belle Fourche SD, Belle Fourche, 19 miles away Days Inn Spearfish, Spearfish, 24 miles away Travelodge Spearfish, Spearfish, 24 miles away Best Western Black Hills Lodge, Spearfish, 24 miles away   Whitewater Near Dennis Reservoir: Redwater, LawrenceCounty, 19 miles away       Class I(II) - 3 miles long (Highway 85 to first bridge)