Mary Reservoir   Be the first to submit input for Mary Reservoir. If you have info on Mary Reservoir, Campbell County, Wyoming please submit it here to improve this web site.          These outdoors activities are available near Mary Reservoir.   Lakes Near Mary Reservoir: Garner Lake, Campbell County, 14 miles away   Public Lands Near Mary Reservoir: Keyhole State Park, Wyoming, 36 miles away Devils Tower National Monument, Devils Tower - WY, 42 miles away   Hotels Near Mary Reservoir: Settle Inn & Suites Gillette N, Gillette, 12 miles away Econo Lodge Gillette, Gillette, 14 miles away Holiday Inn Express Hotel & Suites GILLETTE, Gillette, 14 miles away Days Inn Gillette, Gillette, 14 miles away Candlewood Suites GILLETTE, Gillette, 14 miles away