Southwest Montana, Montana
Beaverhead River Fishing Report: May 18, 2026
Beaverhead River is in a useful fishing window today.
- Status
- good
- Flow trend
- stable
- Best window
- Late afternoon into evening
- Best methods
- nymphs, dry flies
Quick Summary
Beaverhead River is in a useful fishing window today. USGS showed 575 cfs and 1.80 feet at 7:15 AM, with the flow trend stable. Water temperature was Not reported. Start with nymphs, then watch for late-day mayfly, caddis, or midge activity where the water settles.
Conditions Snapshot
| Field | Value |
|---|---|
| Status | Good |
| Flow | 575 cfs at 7:15 AM |
| Gauge Height | 1.80 feet |
| Water Temp | Not reported |
| Clarity | Not reported |
| Trend | Stable |
| Best Window | Late afternoon into evening |
| Best Method | nymphs; dry flies |
| Wadeability | Limited |
Weather
For Dillon, MT, the National Weather Service forecast says: Today: Mostly sunny, with a high near 49. Northeast wind 7 to 18 mph, with gusts as high as 26 mph. Plan around wind, changing light, and any showers or storms rather than assuming a full-day dry fly window.
River Notes
The best starting point is water that matches the current gauge: inside seams, protected banks, riffle drop-offs, and slower buckets rather than the heaviest current. A stable trend is worth watching through the day; if the hydrograph turns sharply upward, clarity and wade safety can change before hatch timing does. Missing field values are left as Not reported rather than filled from guesswork.
Hatch Activity
Current hatch guidance is based on seasonal May patterns for this river system, recent public report context where available, and today’s official gauge/weather check.
| Hatch | Size | Notes |
|---|---|---|
| Midge | 20-24 | Tailwater option in slick water |
| Blue Winged Olive | 18-22 | Best with clouds |
| Caddis | 14-18 | Watch softer banks |
| Scud/sowbug | 14-18 | Tailwater subsurface staple |
Recommended Flies
| Category | Fly | Size | Notes |
|---|---|---|---|
| Dry | Griffith's Gnat | 20-24 | Use over steady risers |
| Dry | BWO Sparkle Dun | 18-22 | Match small olives in softer seams |
| Nymph | Pheasant Tail | 14-18 | Mayfly nymph before hatches |
| Nymph | Caddis Pupa | 14-18 | Swing or dead drift before activity |
| Nymph | Scud or Sowbug | 14-18 | Tailwater staple in slower lanes |
Tactics
Start with nymphs in defined lanes and adjust weight or leader length before changing flies. If fish begin rising, simplify to a single dry or dry with an emerger/dropper and lengthen the leader. In bright or windy periods, return to subsurface presentations along protected banks and broken water. Re-check the gauge before wading new crossings, especially if the trend changes from stable or falling to rising.
Gauge Links
| Gauge | Flow | Temp | Link |
|---|---|---|---|
| Beaverhead River at Barretts MT | 575 cfs | Not reported | USGS 06016000 |
Sources
Official sources checked: USGS station 06016000 and the National Weather Service forecast for the Dillon, MT area. This report is an original Custom FlyBox summary based on current official gauge and weather data, with local public conditions reports reviewed separately for hatch, access, and method context.