Below Ennis Lake the Madison drops through Bear Trap Canyon and then flattens out for the last thirty miles to Three Forks. It is a different river from the Upper: shallower, weedier, warmer, and closer to Bozeman. That combination makes it the most accessible reach and the one most often shut down by summer heat.
Lower Madison — Today's Report
Tuesday, September 22, 2026
Live Data
Updated Sep 21, 7:02 PM MDT
Lower Madison Fishing Report
Ennis Dam to Three Forks
Water Temp (McAllister)57.7°F
Flow Rate (McAllister)1,160 CFS
Water ClarityGood
The Lower is running 1170 cfs and yesterday's reading came in at 59.2°F, which is the number that matters. This river draws warm water off the top of Ennis Lake and cooks in July and August, but from mid-September through June the temperatures are prime, and we're there now. FWP pulled the hoot owl restrictions on August 31 and with these water temps there's zero chance they come back this fall, so you can fish the afternoon and evening without checking the clock. Full disclosure on how it's been fishing: mixed. Reports over the last couple weeks have ranged from tough to pretty good, and I'd call that honest. The fish spent the summer getting harassed in the mornings and resting in the afternoons, and they're still shaking that off. But every cold night resets this river a little more, and the trend is clearly up. The fish that were podded up in the fast, oxygenated water all summer are spreading back out into the runs and flats where they belong. Weed growth is the main variable. Late summer left plenty of vegetation in the river, and it hasn't broken up yet, so you'll foul flies if you fish deep rigs through the wrong water. The upside is the weed edges and channels are exactly where the fish are holding, and the crayfish and scuds living in that salad are what they're eating. Crayfish patterns have been the most reliable producer down here for weeks and that won't change until the water gets properly cold. There are still hoppers on the grassy banks through the warm part of the day, and the BWOs that are about to become the main event on cloudy afternoons will show here same as upstream. Streamer fishing has been hit or miss, but the fish that do eat a streamer down here in fall tend to be the right ones. Bear Trap Canyon is worth the walk right now. Access is on foot only, from the trailhead at the downstream end off Highway 84, and the trail runs about nine miles upstream toward the dam. Every half mile you walk past the first bend thins the crowd, and the pocket water and deep slots up in the canyon have been fishing better than the wade water near the lower access points around Warm Springs and Black's Ford. It's rattlesnake country until the first hard freeze, so watch your feet on the rocky sections. Clarity is good, not gin clear like the Upper, there's a little tint and some drifting weed, but plenty clean to sight fish the flats on a bright day. If you want numbers and consistent action today, I'd still give the edge to the Upper, but if you want elbow room and a shot at a heavy brown that hasn't seen a fly since June, the Lower is the play, and it only gets better from here into October.
Tactics for today
Rig a crayfish pattern under an indicator set shallow enough to tick the weed tops, not plow through them, and dead drift it along the channel edges between weed beds. When the drift ends, let it swing and hang, crayfish eats often come on the rise at the end. On the flats, a hopper with a Duracell dropped 18 inches off the back is the searching rig through the afternoon. In the Bear Trap, high-stick the pocket water with the rubber legs and keep your drifts short, those canyon fish don't need a long look. If you're floating from the dam, get through the first couple miles early, that water gets pounded, and slow down where the river braids below the canyon mouth.
Recommended Patterns
Clouser Crayfish #6-8Duracell Jig #14Pat's Rubber Legs #8BWO Sparkle Dun #18Morrish Hopper #10
The water
Water leaves Ennis Lake off the top, which means it arrives warm. That single fact drives most of what happens on this reach: early hatches in spring, excellent fishing in the shoulder seasons, and hoot owl restrictions through much of the summer.
Bear Trap Canyon, immediately below the dam, is BLM wilderness: a nine-mile walk-in canyon with pocket water and real whitewater. It holds up better in the heat than the valley water below it.
Downstream of the canyon the river spreads out shallow and weedy over a gravel bed. It fishes more like a big spring creek than a freestone, and the trout see a lot of flies.
Access
Bear Trap Canyon (BLM): Wilderness. The developed trailhead sits at the downstream end of the canyon, off Highway 84; the trail follows the bank about nine miles upstream toward the dam. No vehicles, and the whitewater has drowned experienced boaters. Wade it.
Warm Springs: Top of the valley float water, and the reach's main put-in.
Damselfly: Next launch below Warm Springs, above Black's Ford. Common short-float take-out.
Black's Ford: Mid-reach access with a ramp.
Greycliff: Gravel ramp and camping, mid-valley.
Cobblestone: Walk-in access further down the valley toward Three Forks. No boat ramp.
Readings come from USGS gauge 06041000 near McAllister, below Ennis Dam. Water temperature matters more than flow on this reach. Once it holds above 70°F, fishing is hard on the trout no matter what the flow looks like.
Frequently, from mid-July into August. When water temperatures stay high, Montana FWP closes fishing daily from 2 p.m. to midnight. The current report above shows today's water temperature; check FWP for the official restriction list.
When is the Mother's Day caddis hatch on the Lower Madison?
Usually the first two weeks of May, before runoff. It is the best-known hatch on this reach and can produce excellent dry fly fishing for a short window.
Can you fish Bear Trap Canyon?
Yes. It is BLM wilderness below Ennis Dam, reached on foot from the trailhead at the downstream end of the canyon off Highway 84. It holds cooler water than the valley section below it, which makes it a better bet in hot weather.
How warm is too warm on the Lower Madison?
Hooked trout recover poorly once water holds above about 70°F. FWP’s hoot owl criterion is stricter on paper, daily maximum temperatures of 73°F for three consecutive days, but 70°F is where you should stop on your own, restriction or not.