Hatch-chart pattern list
Best Flies for Clark Fork River (Montana)
The Clark Fork River in Montana fishes as both a wade and a float. It is a freestone fishery for Rainbow Trout and Brown Trout, with the most reliable window in June, July, August. The patterns below are matched to the hatch chart we publish for this water. They are not a live report of what other anglers caught this week.
This is not a live report of other anglers' catches. Presence and flow live on the Clark Fork River river page and the Montana destination guide.
What's hatching now
Month, insect, size, and pattern from the Clark Fork River hatch chart. October is highlighted when that month exists in the chart. We do not invent a hatch that is not on the chart.
| Month | Insect | Size | Pattern |
|---|---|---|---|
| January | Midge | #20-24 | Zebra Midge |
| February | Midge | #20-24 | Griffiths Gnat |
| Blue-winged Olive | #20-22 | Parachute BWO | |
| March | Blue-winged Olive | #18-22 | Parachute BWO |
| Midge | #20-24 | Griffiths Gnat | |
| April | Skwala Stonefly | #10-12 | Skwala Dry |
| Blue-winged Olive | #18-22 | RS2 | |
| May | Mothers Day Caddis | #14-16 | Elk Hair Caddis |
| March Brown | #12-14 | March Brown Parachute | |
| June | Golden Stonefly | #6-8 | Stimulator |
| Salmonfly | #4-6 | Sofa Pillow | |
| Caddis | #14-16 | X-Caddis | |
| July | Golden Stonefly | #6-8 | Stimulator |
| Caddis | #14-16 | Elk Hair Caddis | |
| Pale Morning Dun | #16-18 | PMD Sparkle Dun | |
| August | Grasshopper | #8-12 | Dave Hopper |
| Caddis | #14-16 | Elk Hair Caddis | |
| Ant | #14-18 | Foam Ant | |
| September | Blue-winged Olive | #18-22 | Parachute BWO |
| Mahogany Dun | #14-16 | Mahogany Comparadun | |
| October | Blue-winged Olive | #20-22 | Parachute BWO |
| Midge | #20-24 | Zebra Midge | |
| November | Blue-winged Olive | #20-22 | Parachute BWO |
| Midge | #22-24 | Mercury Midge | |
| December | Midge | #22-26 | Zebra Midge |
Nymphs
Subsurface patterns matched to this river's chart and catalog. Fish them at the size the chart lists, not the size that looks good in the bin.
Dries
Dries and terrestrials for the Clark Fork River. If the chart says a size 18 PMD, do not start with a 12.
Streamers
Streamers and wets for stained water, banks, and low light. This is not a claim that streamers are "on" today.
Setup
4X and 5X cover most nymphing. 4X on dries until the fish get picky, then 5X. A 3.0–3.8mm tungsten on the point and a lighter dropper is a default until you see the water. Tight-line the near bank and the heads of pockets. Use an indicator only when you need to search water you cannot euro.
FAQ
- What flies work on the Clark Fork River?
- Start with Zebra Midge and RS2, then match size to the hatch chart for the month you are standing in. The Clark Fork River does not need a 40-pattern box. It needs the right size on the insect that is actually in the drift.
- When is the best time to fly fish the Clark Fork River?
- The editorial window we list is June, July, August, September, October. That is a planning month range, not a guarantee. Shoulder months can fish well if flows and water temperature cooperate.
- Do I need a guide on the Clark Fork River?
- Montana has walk-up wade water and, on some sections, float water. A guide is worth it for a first float or a technical tailwater. A hatch chart and a gauge are enough for a first wade if you already nymph. We list local guides and shops on this page when we have them.
- Where can I see live flow for the Clark Fork River?
- Open the Clark Fork River river page for the USGS gauge, access notes, and the same hatch chart this fly list is built from. We do not publish other people's spots or fish counts.
- Is this a report of what's working now on the Clark Fork River?
- No. Executive Angler does not publish other anglers' catches, GPS, or a crowdsourced hot fly. This page is hatch-chart patterns plus catalog flies. Presence on the river page is gauge and weather only.
Related
River guide
Clark Fork River
Access, hatch chart, USGS gauge.
Destination
Montana
Trip planning for this region.
Pattern
Zebra Midge
Midge
Pattern
RS2
Emerger
Pattern
BWO Sparkle Dun
Dry
Guide
Grizzly Hackle Guide Service
Guide
Missoulian Angler Guide Service
Fly shop
Arrick's Fly Shop
37 Canyon St, West Yellowstone, MT 59758
Fly shop
Beartooth Flyfishing
2925 US-287, Cameron, MT 59720
Nearby water
Beaverhead River
Open the river guide, then its fly list.
Nearby water
Big Hole River
Open the river guide, then its fly list.
Nearby water
Bighorn River
Open the river guide, then its fly list.
Nearby water
Bitterroot River
Open the river guide, then its fly list.













