Greybull River
Fly fishing in Wyoming · Beginner · Best seasons: Summer, Fall
Target Species
Rainbow Trout, Brown Trout
About This Water
Bighorn Basin stream with rainbow and brown trout. Less crowded fishing.
Fishing Recommendations
The Greybull River is one of Wyoming’s best-kept secrets. Flowing out of the rugged Absaroka Mountains southeast of Cody, it is a wild, remote, and often demanding fishery. While it lacks the fame of the nearby Shoshone or Yellowstone rivers, it offers a "true West" experience: high-desert scenery, braided channels, and aggressive fish.
🎣 Location Overview
The Greybull River is a classic freestone stream that transforms from a tumbling mountain creek in the Shoshone National Forest into a meandering, braided river as it enters the high-desert basin.
What makes it special is its remoteness and purity. It is one of the most important strongholds for the Yellowstone Cutthroat Trout. The water is crystal clear (except during runoff) and flows through some of the most grizzly-dense country in the lower 48. Anglers love it because you can spend an entire day on prime water without seeing another soul, casting to fish that aren't nearly as "educated" as those on the Henry's Fork or the Madison.
🐟 Target Species & Behavior
While you requested information on Rainbow and Brown Trout, it is vital to note that the Greybull is primarily a Yellowstone Cutthroat fishery, especially in the upper reaches.
- Rainbow & Brown Trout: These are more prevalent in the middle and lower reaches, particularly below the Wood River confluence. They are opportunistic feeders but can be spooked easily in the shallow, clear runs.
- Behavior: These fish are built for a short growing season. They are highly aggressive toward surface flies.
- Holding Patterns: Look for fish in the "braids." The Greybull splits often; don't ignore the smaller side channels. They hold in classic pocket water, behind large boulders, and in the deep undercut banks carved into the desert soil.
📅 Best Times to Fish
The Greybull is high-altitude and snow-fed, making timing critical.
- Summer (July – August): This is the prime window. Runoff usually subsides by early to mid-July. This is "Hopper-Dropper" season. The fish are looking up, and the water temperatures are ideal.
- Fall (September – October): This is my favorite time. The cottonwoods turn gold, the water levels drop, and the larger Brown trout become more aggressive as they prepare for the spawn. The wind usually dies down compared to the spring.
- Time of Day: During the summer, the "10 AM to 4 PM" window is fantastic for dry fly action. In the heat of August, early mornings are best for streamer stripping.
- Conditions: Avoid the river after heavy mountain rains; the Greybull can "blow out" (turn muddy) very quickly due to the volcanic soils of the Absarokas.
🪰 Recommended Flies & Techniques
Top Fly Patterns
- Dry Flies:
- Hoppers: Pink Pookas, Charlie Boy Hoppers (Size 8-12).
- Attractors: Royal Wulff, Stimulators (Orange/Yellow), and the Purple Haze (Size 12-16).
- Terrestrials: Amy's Ant and Fat Alberts.
- Nymphs:
- Attractors: Prince Nymphs and Copper Johns (Red or Blue).
- Local Favorites: Pheasant Tails and gold-ribbed Hare’s Ears (Size 14-18).
- Streamers:
- Patterns: Black or Olive Wooly Buggers, Gold Sparkle Minnows.
Techniques
- The Hopper-Dropper: This is the bread and butter of the Greybull. Use a buoyant foam hopper on top and a weighted nymph (like a Prince Nymph) 24 inches below.
- Pocket Water Picking: Don't spend too much time in one hole. The fish are spread out. High-stick your dries through the pockets behind rocks.
- Streamer Stripping: In the deeper pools and undercut banks of the lower river, strip a streamer aggressively to trigger a reaction from larger Browns.
💡 Pro Tips & Local Knowledge
- The "Greybull Grind": The riverbed is notorious for "rolling rocks." Wear felt soles or studs, and use a wading staff. It’s a physical river to fish.
- Mind the Wind: The Greybull Basin is a wind tunnel. If the wind picks up, switch to a heavier 6-weight rod and low-profile streamers to keep your line under the gusts.
- The Braid Rule: If the river splits into three channels, the smallest, skinniest channel often holds the most surprising fish. Don't walk past 6 inches of water without looking for a shadow.
- Upstream vs. Downstream: For Rainbows and Cutthroats, focus on the Forest Service land (Upper Greybull). For larger Browns, focus on the stretches further downstream toward the town of Meeteetse (where access allows).
⚠️ Important Information
- Bear Safety: This is Grizzly Country. You are fishing in a high-density bear area. Always carry bear spray on your person (not in your pack) and make noise when walking through thick willows.
- Access: Much of the lower Greybull flows through private ranch land. However, the Pickett Lighthouse and Jack Creek areas provide excellent public access points. Always use a GPS app (like OnX) to ensure you are on public land or within the high-water mark where legal.
- Regulations: Wyoming Game & Fish regulations apply. Always check the current year’s booklet, as there are specific "Catch and Release" sections and lure restrictions designed to protect the native Cutthroat populations.
- Permits: A valid Wyoming fishing license and a Conservation Stamp are required.
The Greybull is a rewarding challenge. If you respect the terrain and the wildlife, it will provide some of the most visual and exciting trout fishing in the Rockies. Tight lines!
Bug Hatches & Matching Flies
| Hatch | Type | Peak months | Time of day | Hook sizes | Matching flies |
|---|---|---|---|---|---|
| Blue Winged Olive (BWO) Baetis spp. | mayfly | April, May, September, October | Late Morning/Afternoon | #18-22 | Parachute Adams #18-22, RS2 #20-22, Pheasant Tail #18-20 |
| Salmonfly Pteronarcys californica | stonefly | June, July | All Day | #4-8 | Chubby Chernobyl (Orange) #6-10, Pats Rubber Legs #4-8, Rogue River Stone #6-8 |
| Pale Morning Dun (PMD) Ephemerella excrucians | mayfly | July, August | Late Morning | #14-18 | Sparkle Dun #16-18, Quill Gordon #14-16, Military Mayfly #16-18 |
| Golden Stonefly Hesperoperla pacifica | stonefly | July | Morning/Afternoon | #8-12 | Golden Chubby #8-12, Twenty Incher #10-12 |
| Spotted Sedge Hydropsyche spp. | caddis | July, August | Evening | #14-16 | Elk Hair Caddis (Tan) #14-16, LaFontaine's Deep Sparkle Pupa #14-16 |
| Yellow Sally Isoperla spp. | stonefly | July, August | Afternoon/Evening | #14-16 | Yellow Sally Foam Stone #14-16, Iron Lotus #14-16 |
| Grasshoppers Orthoptera | terrestrial | August, September | Afternoon | #8-14 | Morrish Hopper #10-12, Parachute Hopper #12-14 |
| Midges Chironomidae | midge | March, April, October, November | Late Morning | #20-24 | Zebra Midge #18-22, Griffith's Gnat #20-24 |