Big Springs & Johnny Sack Cabin – the source of the Henry’s Fork of the Snake River, is also well worth a visit. Because of Big Springs constant 52 degree temperature and crystal clear flow, the Henry’ Fork is a favorite early in the fishing season when other nearby rivers are cold and muddy from the sediment picked up by the melting snow. Big Springs is also near the beginning of a beautiful 5 mile canoe or boat trip along a stretch of a National Scenic Water Trail. Other activities in Island Park include a bicycle ride or hike on the Old Union Pacific railroad bed, a game of golf at the Island Park Resort, a horseback trail ride or a visit to Johnny Sack’s cabin.