Olson Reservoir   Be the first to submit input for Olson Reservoir. If you have info on Olson Reservoir, Valley County, Montana please submit it here to improve this web site.          These outdoors activities are available near Olson Reservoir.   Public Lands Near Olson Reservoir: Hell Creek State Park, Montana, 20 miles away   Marinas On or Near Olson Reservoir: Rock Creek Marina, Fort Peck, 19 miles away