Top 5 Utah Rivers Fishing This Week | May 2026

The Blacksmith Fork Canyon was flowing on the report date at 74 cfs (normal) with a falling trend. Flows were rated fishable on the report date. The Verdict: Excellent Conditions This week’s forecast shows temperatures ranging from 51-69°F. Calm winds support dry fly presentations.

Insect Activity: Golden stoneflies are coming on strong as flows ease back from runoff levels — at 74 cfs and ticking down, look for adults fluttering along the canyon walls in the late afternoon, with golden stone nymph imitations producing in the faster broken water all day. Back it up with a Squirmy Worm #12 or San Juan Worm #14 as a dropper in the deeper pocket water; worms are gold right now as the canyon settles post-runoff. Get on the water today — tomorrow’s 80% storm chance could push flows back up by the weekend.

Where to Fish:Fish a stonefly nymph under an indicator through the pockets between canyon walls, then drop down to a worm pattern in the deeper tailouts.

Gear Tip: Start with a two-fly nymph rig and a yarn indicator early. Shift to dry fly or dry-dropper during hatch windows. 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.

The Mammoth Creek – Hatch Valley was flowing on the report date at 39 cfs (normal) with a stable trend. Flows were rated fishable on the report date. The Verdict: Excellent Conditions This week’s forecast shows temperatures ranging from 50-68°F. Calm winds make indicator nymphing more effective.

Insect Activity: Mid-May in the Hatch Valley means the tail end of Mother’s Day Caddis season — watch for afternoon adult flights between noon and 3pm, and lead with Garcia’s Mother’s Day Caddis #16 in tan or black when fish are visibly rising in the riffles. When the surface action goes quiet, switch to a Sparkle Dun #18 or Rainbow Warrior #18 below an indicator to target fish feeding just sub-surface on caddis emergers. The all-day sunshine and 62°F highs will warm things up nicely through mid-afternoon, concentrating the best feeding windows.

Where to Fish: At 39 cfs Mammoth Creek runs clear and low through Hatch Valley — fish will be spooky, so keep a long leader, stay low on approach, and fish upstream to avoid lining them. Target undercut banks, shaded pools, and the tail-outs of short riffle sections where trout set up and sip emergers in the film. The canal diversion about 3 miles upstream from where Mammoth hits the reservoir marks the special-regulation boundary — know where you are on the water before keeping any fish.

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.

The Rock Creek – Mountain Home was flowing on the report date at 53 cfs (normal) with a stable trend. Flows were rated fishable on the report date. The Verdict: Excellent Conditions This week’s forecast shows temperatures ranging from 50-68°F. Calm winds make indicator nymphing more effective.

Insect Activity: Rock Creek in the Uinta foothills runs cold well into May, and midges are the primary food source until water temps climb past 50°F — a Griffith’s Gnat #20 as a dry or a Rojo Midge #20 dropped 12 inches below it as a trailing emerger covers the morning and midday feeding windows. The slight flow uptick (2%) confirms snowmelt is still feeding the creek, keeping water temps cold but fish metabolisms ticking predictably. Don’t overlook a Rainbow Warrior #18 as a searching nymph between obvious rises — it mimics midge pupae effectively in the freestone riffles and draws fish off the bottom.

Where to Fish: Focus on riffle-to-pool transitions and flat tailouts where fish can feed on drifting midges. The freestone character means fish spread throughout the reach, so target structure — boulders, root wads, undercut banks — rather than hunting deep pools. Tomorrow’s 53% storm chance could bump flows, so fish the lower-gradient sections today for the most stable wading and predictable fish holding water.

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.

The Sevier River – Upper Hatch was flowing on the report date at 89 cfs (normal) with a stable trend. Flows were rated fishable on the report date. The Verdict: Excellent Conditions This week’s forecast shows temperatures ranging from 55-73°F. Calm winds make indicator nymphing more effective.

Insect Activity: The Upper Sevier runs like a spring creek through Hatch — clear water, steady flows, and consistent May caddis hatches make this a dry fly destination right now. Afternoon caddis activity is the main event with Garcia’s Mother’s Day Caddis #16 and Green Weenie #12 both drawing surface takes in the riffles and runs between 1pm and dusk. When fish aren’t rising visibly, swing a Parachute Adams #16 across the tail-outs or dead-drift a Sparkle Dun #18 through the glassy flat water — head-and-tail rises in this section are the classic signal that caddis emergers are in the film.

Where to Fish:The meadow stretches near Hatch offer the most reliable dry fly water, with trout holding in defined current lanes where emergers get trapped in the surface film. Fish the inside bends and current seams with upstream presentations, especially through the 2–5pm caddis window when this section consistently produces its best surface action.

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.

The Upper Duchesne was flowing on the report date at 111 cfs (normal) with a falling trend. Flows were rated fishable on the report date. The Verdict: Excellent Conditions This week’s forecast shows temperatures ranging from 48-66°F. Calm winds make indicator nymphing more effective.

Insect Activity: Freestone conditions support diverse hatches. Caddis and mayflies are active, with stoneflies providing excellent opportunities.

Where to Fish: Higher flows create more holding water. Target deeper runs, tailouts, and slower side channels where fish can hold out of the main current.

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.