Except for the Firehole River and the Yellowstone River above the falls, all waters offer great fishing experiences. Turn to early AMs and evening hours for the best action on the Madison River. Slough Creek is fishing very well with hopper season not far away. Same applies for Fall River Basin streams. Small streams such as the upper Gallatin River, Grayling Creek, Boundary Creek, Mountain Ash Creek, Fan Creek, and the upper Gibbon River below Virginia Cascades provide great action for those using traditional attractor patterns ( sizes 12-18). Beula Lake continues to provide the consistently fastest action in Park waters with Riddle Lake not far behind.