Specializing in Homes, Improved Lots, Raw Land, River Front Homes, River Front Sites, and Commercial Properties in Swan Valley, Idaho. Swan Valley Idaho is a picturesque community on the banks of the South Fork of the Snake River, the best wild trout fishery in the lower 48 states. The Caribou Mountains to the south, the Palisades Range to the east and the Big Hole Range to the north makes Swan Valley a spectacular place to be. As a part of the Yellowstone ecosystem they benefit from the tremendous vast tracks of wilderness in the surrounding mountains. This gives them unsurpassed outdoor recreation opportunities as well as their good neighbors, the wildlife.