The Lower Madison is the stretch of river starting from the Madison Dam on Ennis Lake, and flowing down to the confluence of the Missouri roughly 35 miles downstream. Below the dam the river starts out in a steep canyon with towering cliffs, and whitewater throughout. This first seven miles is consider the Bear Trap Canyon, and is accessible by a trail running along river. You can easily hike upstream from the parking lot at the end of the Bear Trap road, or hike downstream from the dam which is more challenging due to steep, rocky terrain. Boating through the canyon is for experienced rafters only, as there are some big whitewater rapids in the first few miles. There is much less fishing pressure as you walk further into the canyon, and there are good numbers of Rainbow and Brown trout throughout the canyon.
The canyon stretch mellows out where the river meets highway 86 at the Warm Springs access, and the river slows down as it travels through more open countryside. Warm Springs to Blacks Ford offers easy access and good numbers of trout, but it can get very busy with recreational floaters in the high summer months. The river is wider and slower here with very little in the way of rapids. Fishing on foot or by boat is much easier in this section. Much of the river here is shallow with weed beds and “buckets” throughout. Buckets are the deeper depressions amongst the shallow riffles of the Lower Madison, and fish will often take refuge in these buckets. Trout numbers thin out below Greycliff access down to the Missouri confluence at Three Forks. There are some large Brown Trout down there, but you usually won’t catch large numbers of fish below Greycliff.
Spring and autumn are often the best time to fish the Lower Madison. The water can get too hot at times during high summer which can stress fish and result in fish kills. Up in the Bear Trap Canyon there is lots of structure which creates plenty of holding water for trout. Dry fly and streamer fishing can be good at times, but nymphing is usually the most productive. The dry fly action is usually better in the canyon, with better hatches and less fishing pressure. On warmer, winter days you may find some pods of fish rising to midges. Spring and fall baetis hatches can offer some of the best dry fly action up in the canyon on cloudy days. Mothers Day Caddis can be fantastic, as it is the first big caddis hatch of the season. Depending on weather this can occur in the weeks around Mothers Day. May and June can offer a variety of hatches including, caddis, pale morning duns, yellow sallies, march browns, goldenstones and salmonflies; although, stonefly hatches are usually not great on the Lower. Fishing terrestrials such as hoppers, ants and beetles can offer good dry fly action later in summer when the weather is not too hot. Streamer fishing can be a fun and productive way to catch fish, especially in the fall months when the brown trout get aggressive for the spawning season. Below the canyon you will more often find the fish eating nymphs down in the deeper buckets amongst the weed beds. Crayfish are a huge part of the food chain here, and often times a crayfish pattern with a smaller caddis or mayfly nymph dropper will catch fish. San Juan Worms can also work particularly well. Below Greycliff you usually won’t find many fish rising, but these fish like bigger flies like Buggers and Zonkers.
The Lower Madison offers a good diversity of water to fish, and the large average size trout make for some fun fishing.