Wade · Best fit82/100
Wading is in play only where your chosen access has clear footing, legal entry, and no forced crossings.
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Fly fishing report · West
Beaverhead River at Dillon
A reach-specific Beaverhead page for anglers deciding whether the Dillon water has the flow, public access, and trout-friendly conditions for a technical brown-trout day.
Check flow & weatherToday's river scoreHigh source confidence
82
Good
Best option: Wade.
Wading is in play only where your chosen access has clear footing, legal entry, and no forced crossings.
Updated Jul 13, 11:17 PM UTCUsually refreshes about every 45 minutes
Recommended approachWade
Mode scores adjust the river-wide score for the risks of wading, bank fishing, or floating.
Bank / edgeCheck
This report does not describe this as a primary mode. Verify legal access, depth, launches, and retreat options before planning around it.
Float82/100
A float is in play where this report supports boat access and wind, releases, and shuttle logistics are manageable.
Confirm before you leave
Flow and weather right now.
Use the flow trend to confirm the score before you leave. Weather can change the safest and most productive fishing window.
Loading current flow and weather.
River strategy
Treat Dillon as the transition reach between the classic tailwater and the warmer irrigation valley below.
This stretch fishes best when flows stay steady enough to preserve weed edges, seams, and depth without turning the river into a heavy irrigation push. It is still the Beaverhead, but the Dillon reach is not the same all-day tailwater game as the canyon immediately below Clark Canyon Dam.
- Montana FWP describes the Beaverhead as a premier brown-trout river and notes seasonal recreation rules from the third Saturday in May through Labor Day.
- FWP's Beaverhead drainage plan says the true tailwater runs about 16 miles below Clark Canyon Dam before Barretts Diversion Dam, while the lower river near and below Dillon is more heavily influenced by irrigation demand.
- FWP's Cornell Park acquisition documents identify Cornell Park near Dillon as the only public access that allows floating to downstream Selway Park.
- Use RiverReports as the quick visual chart, but keep USGS 06017000 near Dillon as the official flow reference before you commit to wading or floating.
Why this score moved
HeatUse caution
The NWS forecast is near 92F. Fish early and verify water temperature where trout stress is possible.
FlowHelps score
USGS shows 163 cfs with a stable over about 6 hours trend. same-date USGS history (1951-2024, 33 readings) puts the normal middle range around 112 cfs-252 cfs. Flow is inside the same-date normal range, so weather, temperature, and access become the next checks.
SeasonHelps score
Summer mornings: Still productive when flows are stable, but best handled as a short technical session.
Public alertsHelps score
No active NWS alert was returned for this forecast point.
Fishing usefulnessHelps score
Skip or pivot when irrigation color takes over, afternoon heat makes trout handling questionable, recreation-rule timing or current restrictions do not fit the plan, or named public access is not clearly open.
Read the water
What changes the plan.
The Dillon reach is strongest when flows are stable, aquatic weeds are still fishable, and overnight temperatures keep trout active into late morning. It loses value quickly when irrigation swings muddy the river, weeds collapse, or heat turns the day into a short early window.
Steady moderate flow
Best setup for technical nymphing, weed-edge drifts, and short float coverage between public access points.
Low clear flow
Fish early, get lighter, and shorten your target water to depth, weeds, and shade instead of forcing broad flats.
Irrigation push or color
Usually a sign to avoid forcing the lower reach and move to colder, cleaner water upstream.
Hot bright afternoon
The river can still look good but fish far smaller than the morning window if temperatures climb.
Field plan
Fish it with intention.
Best flows
Use RiverReports and USGS 06017000 near Dillon together. Stable moderate flow that keeps weed edges and seams defined is the best signal; dirty irrigation color, a sharp push, or hot low water should move the day.
When to skip
Skip or pivot when irrigation color takes over, afternoon heat makes trout handling questionable, recreation-rule timing or current restrictions do not fit the plan, or named public access is not clearly open.
Local plan
Start with the Dillon gauge and one named access plan such as Cornell Park or Selway Park. Fish a short technical window early, then either float legally or move upstream if the lower valley feels too warm or flat.
Backup water
If Dillon is warm, dirty, crowded, or too flat, compare the upper Beaverhead for colder technical water, Twin Bridges for a float-oriented lower-river look, or the Big Hole for a different southwest Montana trout plan.
Hatches & flies
Bring a flexible box.
TimingWhat to watchUseful flies
SpringMidges, BWOs, and early caddisZebra midge, BWO emerger, soft hackle, caddis pupa
Reviewed pattern · report says “Zebra midge”Zebra MidgeLook for a very slim tapered thread body, evenly spaced contrasting wire rib, a small bead, and no tail or wing. The reviewed classic is black with silver wire and a silver bead. Red, olive, brown, glass-bead, jig-hook, resin-coated, or tailed forms must remain labeled variations rather than replacing the classic identity.See photos & how to fish it ↗
Reviewed family · report says “BWO emerger”Blue-Winged Olive PatternsBWO describes a hatch group, not one fly. Nymph, emerger, dry, cripple, and spinner profiles must stay separate because they occupy different parts of the water column.See family guide ↗+ 2 more reviewed guides in the Fly Box Early summerPMDs, caddis, yellow salliesPMD cripple, sparkle caddis, pheasant tail, yellow sally
Reviewed family · report says “PMD cripple”Pale Morning Dun PatternsPMD names an insect group, not one fly. Pale nymphs, trailing-shuck emergers, upright or low-riding duns, cripples, and spent-wing spinners stay visibly separate.See family guide ↗
Reviewed family · report says “sparkle caddis”Caddis Patterns by StageCaddis is not one fly. Larvae live below, pupae and emergers rise through the column, tent-wing adults ride or move on top, and spent forms create other silhouettes.See family guide ↗+ 2 more reviewed guides in the Fly Box SummerTricos, caddis, terrestrialsTrico spinner, ant, hopper-dropper, caddis emerger
Reviewed pattern · report says “Trico spinner”Trico SpinnerThe reviewed dry form is extremely sparse and flat, using a black body or thread head and pale spent wing. A weighted Sunken Trico Spinner is a separate variant.See photos & how to fish it ↗
Reviewed family · report says “ant”Ant PatternsAnt patterns can be foam, fur-bodied, winged, or sunken. The narrow waist and paired body lobes matter more than one material recipe.See family guide ↗+ 1 more reviewed guide in the Fly Box FallBWOs, midges, streamer windowsParachute BWO, zebra midge, small sculpin, leech
Reviewed family · report says “Parachute BWO”Blue-Winged Olive PatternsBWO describes a hatch group, not one fly. Nymph, emerger, dry, cripple, and spinner profiles must stay separate because they occupy different parts of the water column.See family guide ↗Reviewed pattern · report says “zebra midge”Zebra MidgeLook for a very slim tapered thread body, evenly spaced contrasting wire rib, a small bead, and no tail or wing. The reviewed classic is black with silver wire and a silver bead. Red, olive, brown, glass-bead, jig-hook, resin-coated, or tailed forms must remain labeled variations rather than replacing the classic identity.See photos & how to fish it ↗+ 2 more reviewed guides in the Fly Box 01
Start with the Dillon gauge, then decide whether the river still has enough shape to justify technical fishing instead of a blind confidence stop.
02
Fish the seams beside weed beds, cutbanks, and defined bucket water rather than trying to cover every inch of the valley channel.
03
If you float, keep it disciplined and centered on named public access instead of assuming convenient pull-outs are legal.
04
When the lower river gets warm or inconsistent, move up the drainage rather than convincing yourself the Beaverhead name will save the day.
Access & responsibility
Know the entry. Know the exit.
Check Montana's current fishing regulations before you fish. Use the statewide Beaverhead drainage rules along with any active drought, temperature, or recreation restrictions that Montana FWP posts during the season.
Cornell Park Fishing Access Site
FWP's Dillon-area public access with walk-in opportunities and the key upstream launch for the Selway Park float.
Selway Park Fishing Access Site
FWP downstream public access used as the natural lower end of the Cornell Park float plan.
Named public river corridor near Dillon
Stay with signed public entries and FWP-managed sites instead of assuming every roadside bank is open.
Transparent sources
Check the facts behind the plan.
Last material review: 2026-05-31
flowRiverReports: Beaverhead River near DillonflowUSGS Beaverhead River near DillonregulationMontana FWP fishing regulationsregulationMontana FWP restricted-use river permitsbackgroundMontana FWP Beaverhead River drainage planaccessMontana FWP Cornell Park Fishing Access Site acquisitionaccessMontana FWP Cornell Park streambank restoration EAaccessMontana FWP Selway Park Fishing Access Site mapaccessMontana stream access lawsafetyNational Weather Service forecast point near Dillon
Common questions
Before you leave.
What should I check first on the Beaverhead at Dillon?+
Start with RiverReports and USGS 06017000 near Dillon, then check current Montana regulations and any FWP closure or restriction notices.
Can I float from Cornell Park to Selway Park?+
Yes, that is the main public float connection FWP identifies for this Dillon reach, but confirm current access status and low-clearance hazards before you launch.
Is this the same as the classic upper Beaverhead tailwater?+
No. The Dillon reach is still technical brown-trout water, but it carries more irrigation and valley-season influence than the tighter tailwater closer to Clark Canyon Dam.