Ruby River
Ruby Valley · Alder to Twin Bridges
SW Montana, USA
Open live forecast →Target species: Brown and Rainbow.
Stream gauge: 06019500. Flow and water temperature update on every refresh.
Weekly AI Outlook as of 06/05/26
Ruby's sitting at 178 cfs — still running high and off-color from runoff, but clearing daily as we head into prime season. PMDs and caddis are staged and ready once visibility improves. Backcountry Angler notes good nymph fishing with rubberlegs and prince nymphs producing despite current conditions. Watch for the weekend cool-down and rain to accelerate clearing, then expect classic Ruby caddis action to fire as water drops toward fishable clarity.
- Flow: 178 cfs — still elevated from runoff but dropping. Ruby typically clears by late June, and we're tracking toward that timeline.
- Hatches: PMDs and caddis staged for post-runoff emergence. Currently nymphing with rubberlegs and princes while waiting for clarity.
- Water Temp: Likely 50-55°F range — cooling weekend will help settling while keeping temps in the productive zone for trout.
- Best Window: Midday nymphing in deeper slots. Once river clears, expect evening caddis hatches to be the main event.
Generated weekly from live USGS gauge readings, weather forecasts, and recent fly shop reports. Updates Friday mornings.
About this Water
- Freestone
- Best months: June–Aug, peak June–July
The Ruby is a small, overlooked tributary of the Jefferson flowing through a remote valley in SW Montana. It holds surprising numbers of brown and rainbow trout for its size, and the canyon sections above Alder have a genuinely wild character rarely found on accessible Montana streams. The Ruby is a perfect destination for anglers seeking solitude and wild fish over celebrity water.
Despite flowing through private ranch country in its lower reaches, the Ruby River has excellent public access in the upper canyon via BLM land — a hidden gem that most Montana anglers have never fished.
January Outlook
January on the Ruby River — the small Montana brown trout stream that flows through the quiet Ruby Valley southwest of Sheridan is in winter dormancy. The Ruby is a freestone river with no tailwater influence. Fish are cold and lethargic. This is a planning month for spring and summer fishing.
Productive Patterns
- Planning season — Ruby River not productive in January
- Small Nymph (size 20-22 in brief warm spells)
- Midge (if mild day occurs)
- Tie late-season patterns for April opening
Tips
The Ruby River receives almost no winter fishing attention. In extreme mild spells, midges may be present but fishing is marginal. Better to wait for April's pre-runoff window. Use this month to scout access points and plan the season.
Water Notes
Water 32-40°F. Freestone Montana winter. Low flows, possibly iced in cold stretches. Not productive for fishing in January.
February Outlook
February on the Ruby River is Montana's deep winter. The small freestone stream is cold and largely unfishable. Snow covers the Ruby Valley. The brown trout are dormant in the deepest pools waiting for spring. Planning season for the prime April-September window.
Productive Patterns
- Planning season — wait for April
- Tie Ruby River patterns: PMD, BWO, Hopper, Caddis
- Research access points and float logistics
- Tie small midge and nymph patterns for early season
Tips
The Ruby Valley is spectacularly remote and quiet in winter. Plan your access strategy — the Ruby has some private land sections. BLM access points provide good public water. The Beaverhead-Deerlodge National Forest provides forest road access to the upper Ruby.
Water Notes
Water 32-40°F. Deep Montana winter. River may have ice along edges. Not fishable in typical February. Wait for April.
March Outlook
March on the Ruby is still winter in the Ruby Valley, but signs of spring begin. Midges can hatch on warm afternoons. The trout begin stirring in the deeper pools. Pre-runoff fishing is possible by late March in mild years. Flows are still low and fish are concentrated.
Productive Patterns
- Midge (size 22-24, late month warm spells)
- Zebra Midge
- BH Pheasant Tail (small)
- Planning season — main season starts April
Tips
A warm late-March day can provide brief excellent midge fishing on the Ruby. Fish the slow pools and runs where trout concentrate in winter. April is the real start — don't get burned by cold March trips. Check conditions before making the drive from Dillon or Bozeman.
Water Notes
Water 34-44°F. Late winter/early spring. Runoff typically doesn't begin until late April. Some midge activity on warm afternoons.
April Outlook
April on the Ruby is a quiet pre-runoff window before the May blow-out. Small nymphs and midge patterns work well in the clear, cold water. The Ruby Valley's brown trout are hungry after a long Montana winter.
Productive Patterns
- Midge (size 20-22)
- BH Pheasant Tail
- Mercury Blood Midge
- Zebra Midge
Tips
The Ruby is a small, intimate brown trout river. Approach carefully — fish spook easily in the clear spring water. Light tippet (5-6X) is essential.
Water Notes
Water 38-48°F. Cold spring conditions. Clear and low. Best fishing is in mid-morning when temperatures warm.
May Outlook
May sees runoff begin from the Snowcrest and Gravelly ranges, typically clouding the Ruby by mid-month. Fish the early weeks before runoff arrives — the PMD and BWO hatches in early May are outstanding.
Productive Patterns
- PMD Parachute
- BWO Parachute #18
- BH Hare's Ear
- Elk Hair Caddis #16
Tips
Fish the first two weeks of May before runoff clouds the water. The Ruby's brown trout are very catchable in the pre-runoff window on dry flies and nymphs.
Water Notes
Water 44-56°F. Pre-runoff clarity gives way to milky flows by mid-May. Fish early in the month.
June Outlook
The Ruby clears from runoff by mid-to-late June. The river is small enough that it recovers quickly. Caddis hatches are prolific once the water drops. The upper Ruby above Alder is particularly fine with remote access.
Productive Patterns
- Elk Hair Caddis #14-16
- Stimulator
- PMD Comparadun
- BH Soft Hackle Caddis
Tips
Mid-June through September is prime Ruby time. The river is easily waded and the browns are very responsive. The lower Ruby below the reservoir has larger fish.
Water Notes
Water 50-60°F. Clearing from runoff by June 20-25 in most years. Caddis hatches abundant once clear.
July Outlook
July is prime Ruby River season. Caddis, PMDs, and terrestrials all produce. This is a classic small Montana brown trout stream — intimate, clear, and overlooked in favor of the famous Beaverhead nearby. The Ruby deserves more attention.
Productive Patterns
- Dave's Hopper
- Elk Hair Caddis
- PMD Parachute
- Royal Wulff
Tips
The Ruby fishes best with stealthy approaches. Tight casts to undercut banks and willows produce the largest browns. The stretch above Alder near Laurin is particularly good.
Water Notes
Water 58-66°F. July flows are low and clear. Fish best in morning and evening. Afternoon heat can put fish down.
August Outlook
August hopper fishing on the Ruby is excellent. Small brown trout dominate the riffle sections, but 16-18 inch fish are in the deeper pools. The Ruby valley's solitude is striking — minimal angling pressure by any Montana standard.
Productive Patterns
- Parachute Hopper
- Dave's Hopper
- Royal Wulff (attractor)
- Elk Hair Caddis (evening)
Tips
Hopper fishing along the grassy Ruby River banks is excellent in August. Fish early and late. The river can be warm mid-afternoon — shift to shaded sections or take a midday break.
Water Notes
Water 62-68°F. Low summer flows. Warm mid-afternoon — best fishing in morning and evening.
September Outlook
September brings cooling temperatures and excellent fall conditions on the Ruby. BWO hatches resume on cool overcast days. Brown trout become pre-spawn aggressive and streamer fishing improves. The Ruby valley in September is peaceful and scenic.
Productive Patterns
- BWO Parachute #18
- Elk Hair Caddis
- Streamer (olive/white)
- Hopper (early month)
Tips
September BWO hatches on cold mornings are excellent. Streamer fishing in September for pre-spawn browns is underutilized on the Ruby. The fish are not large but they are wild and responsive.
Water Notes
Water 52-60°F. Fall cooling. Excellent September conditions with light pressure.
October Outlook
October brown trout spawning on the Ruby. Pre-spawn fish are aggressive in the weeks leading up to spawning. The Ruby Valley turns gold with cottonwood and aspen. BWO hatches on overcast days. Avoid targeting fish on visible redds.
Productive Patterns
- Streamer (pre-spawn aggression)
- BWO Parachute #18
- Soft Hackle
- BH Pheasant Tail
Tips
October is the last good month on the Ruby before winter closes it down. Streamer fishing for pre-spawn brown trout can be excellent. Treat all fish carefully during spawning season. The lower Ruby near Laurin has larger fish concentrations.
Water Notes
Water 44-52°F. Fall cooling. Brown trout spawning activity. Season winds down for most casual anglers. Excellent conditions through mid-October.
November Outlook
November on the Ruby is very late fall — cold and often snowy. Brown trout have spawned and are recovering in the deeper pools. The season has effectively ended for most anglers. The Ruby Valley is quiet and wild.
Productive Patterns
- Planning season — Ruby wind-down
- Very small nymphs on brief warm days
- Midge Cluster
- Zebra Midge (size 22)
Tips
Late November fishing on the Ruby is marginal at best. A mild warm spell might produce a few fish on midges in the slow pools but the effort-to-reward ratio is low. Better to wait for April. Use this time to tie flies and plan next season.
Water Notes
Water 36-44°F. Late fall Montana conditions. Flows minimal. Fish dormant in deepest holes. Season effectively over.
December Outlook
December — the Ruby River is in Montana winter. The small brown trout stream is frozen or near-frozen. The Ruby Valley is blanketed in snow. Brown trout are surviving the winter in deep cold-water refuges. The season begins again in April.
Productive Patterns
- Planning season — Ruby opens with Spring
- Tie PMD, Caddis, Hopper for coming season
- Research access points on BLM and National Forest land
- Plan Ruby Valley camping and fishing trip logistics
Tips
The Ruby River in December is a beautiful but inaccessible winter landscape. The fish will be there in April. Plan a spring trip to the Ruby Valley combining the pre-runoff window in April with the PMD hatches in May for the finest experience.
Water Notes
Water 32-38°F. Montana winter. Likely iced. Season opens in April. Plan ahead.
Hatch Calendar
| Insect | Peak | Active | Size | Productive Patterns |
|---|---|---|---|---|
| Blue Winged Olive Baetis tricaudatus |
Apr, Oct | Mar, Apr, May, Sep, Oct | #18–22 |
|
| Pale Morning Dun Ephemerella inermis |
Jul | Jun, Jul, Aug | #16–18 |
|
| Caddis Hydropsyche / Brachycentrus spp. |
Jul, Aug | May, Jun, Jul, Aug, Sep | #14–18 |
|
| Yellow Sally Isoperla / Chloroperlidae |
Jul | Jun, Jul, Aug | #12–16 |
|
| Hoppers Acrididae / Tettigoniidae |
Aug | Jul, Aug, Sep | #8–12 |
|
| Trico Tricorythodes spp. |
Aug | Aug, Sep | #20–24 |
|
Access & Approach
Alder, MT. Montana FWP access sites scattered through the valley. Upper canyon sections are walk-in on public land. Very light pressure most days — bring your own scouting ability.
Nearby Fly Shops
- The Stonefly Inn & Fly Shop
- Madison River Fishing Company
- Backcountry Angler
- The Tackle Shop
Regulations & License
Fishing in Montana requires a current license. Always verify season dates, bag limits, and any special-regulation waters before you fish.
Montana fishing regulations & license →
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About Current
Ruby River conditions on Current combine real-time flow data (USGS, WSC, CDEC, CEHQ), weather, tide predictions, hatch probabilities calibrated to this specific water, and recent fly shop reports from the area.
Ruby River is one of 245 hand-curated waters in Current. The app and web forecast also generate AI outlooks for any unlisted river, lake, or saltwater flat anywhere in the world — drop a pin or paste a name and Current produces a fresh seasonal outlook with weather, flow context, and recommended techniques.
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