Three Forks Reservoir   Be the first to submit input for Three Forks Reservoir. If you have info on Three Forks Reservoir, Natrona County, Wyoming please submit it here to improve this web site.          These outdoors activities are available near Three Forks Reservoir.   Whitewater Near Three Forks Reservoir: Powder River - Middle Fork, Washakie JohnsonCounty, 17 miles away       Class II-V - 12 miles long (Forest Service Road bridge Close to county line to Highway 190)