The South Fork Flathead River originates at the confluence of Danaher and Youngs creeks in the Bob Marshall Wilderness Area and flows north, unimpeded for over half its length. Noted for the extreme beauty of its setting and course, the South Fork runs its first 40 miles within the Bob Marshall between the Continental Divide on the east and the Swan Range on the west. From its headwaters to the Spotted Bear River, it is classified a Wild River under the National Wild and Scenic Rivers Act. Access to float the South Fork requires quite a commitment - packing in gear by foot or horseback for 20 miles to begin this wilderness float and the same when the ride is finished. The beauty, fishing, and serenity of the float make it worth the effort. Many backpackers and horse parties enjoy portions of the river as well. An abrupt change in the river results from Hungry Horse Dam, 5 miles above the mouth, which creates the 35-mile-long Hungry Horse Reservoir. Completed in 1952, the dam has served two oppositional purposes for the fisheries of the South Fork - blocking upstream fish migrations from Flathead Lake and effectively isolating the drainage from that fishery, while above the dam maintaining the most intact native fish ecosystem remaining in western Montana.