Guesanborn Reservoir   Be the first to submit input for Guesanborn Reservoir. If you have info on Guesanborn Reservoir, Garfield County, Montana please submit it here to improve this web site.          These outdoors activities are available near Guesanborn Reservoir.   Public Lands Near Guesanborn Reservoir: Hell Creek State Park, Montana, 33 miles away Little Bighorn Battlefield National Monument, Crow Agency - MT, 69 miles away