Top 5 Montana Rivers Fishing This Week | May 2026

The Boulder River is currently flowing at 141 cfs (normal) with a stable trend. Flows are fishable today. The Verdict: Excellent Conditions This week’s forecast shows temperatures ranging from 60-78°F. Calm winds make indicator nymphing more effective.

Insect Activity: The Boulder is in a quiet stretch between hatches right now, with non-insect food sources carrying the day. Squirmy Worms in size 12 pink or red and San Juan Worms are the most consistent producers — trout are keying on them in the deeper riffles. Watch for a sparse late-morning caddis flurry; Garcia’s Mother’s Day Caddis in size 16 tan can draw surface strikes before the afternoon thunder builds.

Where to Fish: At 141 cfs the Boulder is wading at its best — knee-deep riffles above and below town give way to undercut banks and slower runs worth probing with a bead-head nymph rig. Focus your drifts along the seams where fast water meets the inside of bends, and work any rootwad or boulder shadow with a Muddler Minnow on the streamer rod if hatches stay sparse. Beat the 4pm thunderstorms by getting on the water early — morning light and cool temps put fish in a feeding mood before the heat sets in.

Gear Tip: Start with a streamer rig in softer edges. Switch to a two-fly nymph rig and a yarn indicator as flows settle. A 9-foot 5X leader with light tippet keeps the rig natural in these flows.

Presentation: Start shallow, then add weight or depth as you move into deeper runs and pockets. Use longer drifts to cover tailouts and seam water.

Regulations: []

The Dearborn River is currently flowing at 154 cfs (normal) with a rising trend. Flows are fishable today. Water Temperature: 51°F (prime). The Verdict: Excellent Conditions This week’s forecast shows temperatures ranging from 63-81°F. Calm winds make indicator nymphing more effective.

Insect Activity: With no active insect hatch on the Dearborn right now, subsurface searching patterns are your best bet. Atomic Stones in size 10 are drawing strikes — golden stonefly nymphs are active in this Central Montana reach even before the adults show — and a Rainbow Warrior size 18 behind them as a trailing dropper fills in the gaps. On a sunny 86°F afternoon like today, look for a brief caddis or PMD window in the shaded, slower stretches after 6pm.

Where to Fish: The Dearborn runs clear and wadeable at 154 cfs, with pocket water and gravel runs alternating through the canyon above its mouth on the Missouri. Work your way up from the bigger pools at the lower end, where fish stack in the tail-outs, then pick through the riffle-to-run transitions with a tight-line nymphing setup. If the afternoon is slow, swing a Muddler Minnow size 8 through the deeper slots near the canyon walls — brown trout in this drainage respond well to a swung streamer on hot, bright days.

Gear Tip: Start with a streamer rig in softer edges. Switch to a two-fly nymph rig and a yarn indicator as flows settle. A 9-foot 5X leader with light tippet keeps the rig natural in these flows.

Presentation: Start shallow, then add weight or depth as you move into deeper runs and pockets. Use longer drifts to cover tailouts and seam water.

Regulations: []

The Jefferson River is currently flowing at 1550 cfs (normal) with a falling trend. Flows are fishable today. Water Temperature: 56°F (prime). The Verdict: Excellent Conditions This week’s forecast shows temperatures ranging from 62-80°F. Calm winds make indicator nymphing more effective.

Insect Activity: At 1,550 cfs the Jefferson is running on the high side of normal for late May, and that turbulence pushes fish toward softer water and loads up the drift with dislodged food. Squirmy Worms size 12 and San Juan Worms are the bread-and-butter — dead-drifted along the bottom through eddies and current seams. Garcia’s Mother’s Day Caddis size 16 is worth watching for in the evening, when adults can still pop off the slower inside bends and draw opportunistic surface takes.

Where to Fish: Wading is impractical at these flows — a drift boat or pontoon is the right call on the Jefferson near Twin Bridges. Float the inside seams hard, dropping anchor near the large, slow eddies on river-right where silt collects and trout hold just outside the current break. A Muddler Minnow or streamer swung through the deeper outside bends and along the willow-bank cut lines can produce explosive takes from the big browns this section is known for. Plan your float to be off the water before the afternoon thunderstorm window that’s showing through most days this week.

Gear Tip: Start with a streamer rig in softer edges. Switch to a two-fly nymph rig and a yarn indicator as flows settle. A 9-foot 5X leader with light tippet keeps the rig natural in these flows.

Presentation: Start shallow, then add weight or depth as you move into deeper runs and pockets. Use longer drifts to cover tailouts and seam water.

Regulations: []

The Madison River is currently flowing at 430 cfs (normal) with a rising trend. Flows are fishable today. Water Temperature: 58°F (prime). The Verdict: Excellent Conditions This week’s forecast shows temperatures ranging from 56-74°F. Calm winds make indicator nymphing more effective.

Insect Activity: The Upper Madison is flirting with its late-May PMD and caddis overlap — watch for Pale Morning Dun spinners hovering over the riffles from 10am to noon and a caddis presence picking up through late afternoon. Garcia’s Mother’s Day Caddis size 16 is still effective, and a Klinkhammer Special size 16 in olive-tan covers both insects well on the surface. In between hatches, a Squirmy Worm size 12 or Rojo Midge size 20 under an indicator through the deep slots keeps fish coming to the net.

Where to Fish: At 430 cfs the Upper Madison above Quake Lake is in prime wading shape — pick your way along the gravel bars and work the braided channels where the current concentrates food. The long, slick tailouts in the slower meanders are where the best PMD action happens; position downstream and cast upstream into the head of the flat. Cooler temps (78°F today vs. the mid-80s downstream) keep the fish actively feeding throughout the day, so don’t feel rushed — morning and early afternoon sessions both produce well here right now.

Gear Tip: Start with a streamer rig in softer edges. Switch to a two-fly nymph rig and a yarn indicator as flows settle. A 9-foot 5X leader with light tippet keeps the rig natural in these flows.

Presentation: Start shallow, then add weight or depth as you move into deeper runs and pockets. Use longer drifts to cover tailouts and seam water.

Regulations: Artificial flies & lures only; Barbless hooks required; Catch and release required; No bait allowed

The Madison River is currently flowing at 901 cfs (normal) with a rising trend. Flows are fishable today. Water Temperature: 52°F (prime). The Verdict: Excellent Conditions This week’s forecast shows temperatures ranging from 62-80°F. Calm winds make indicator nymphing more effective.

Insect Activity: The Ennis section is running at 901 cfs — high but within normal range for peak runoff season — and the trout are gorging on dislodged food funneled through the riffles. Squirmy Worms size 12 are the top producer right now, especially in the soft water adjacent to the main current. Garcia’s Mother’s Day Caddis size 16 continues to bring fish up in the evening, with adults skating the slow eddies; a Chernobyl Ant size 12 works as an attractor searching pattern through the afternoon when hatches pause.

Where to Fish: High flows on the Ennis Madison push fish to the margins — focus on the downstream tails of islands, the inside bends, and any slack water behind mid-river boulders rather than trying to wade the main current. A drift boat gives you the best access to the classic riffled runs below Ennis, where you can work a two-fly nymph rig along every seam systematically. On foot, look for access points where you can wade into a back-channel or smaller braid and fish the pocket water more intimately — these calmer threads hold fish stacked tight to the banks in these flow conditions.

Gear Tip: Start with a streamer rig in softer edges. Switch to a two-fly nymph rig and a yarn indicator as flows settle. A 9-foot 5X leader with light tippet keeps the rig natural in these flows.

Presentation: Start shallow, then add weight or depth as you move into deeper runs and pockets. Use longer drifts to cover tailouts and seam water.

Regulations: Artificial flies & lures only; Barbless hooks required; Catch and release required; No bait allowed