Lochsa River
Fly fishing in Idaho · Intermediate · Best seasons: Summer, Fall
Target Species
Cutthroat Trout, Steelhead
About This Water
Wild and Scenic River along Highway 12. Native cutthroat and steelhead in beautiful canyon.
Fishing Recommendations
The Lochsa River (pronounced "Lock-saw") is one of the crown jewels of the American West. Located in north-central Idaho, this "Wild and Scenic" river flows through the Nez Perce-Clearwater National Forests. It is a high-gradient, boulder-choked, freestone river that offers some of the best dry-fly fishing for native Westslope Cutthroat trout in the world.
🎣 Location Overview
The Lochsa is defined by its rugged beauty and crystal-clear water. Flowing alongside Highway 12, it provides roughly 70 miles of accessible water, yet it retains a remarkably wild feel.
What makes it special is the pocket water. The river is a continuous staircase of riffles, runs, and deep emerald pools carved out of granite. Because there are no dams, the river is entirely dependent on snowpack. This means it runs high and dangerous in the spring but settles into a fly-fisher’s paradise by mid-summer. Anglers love it because the fish are wild, native, and incredibly "looking up"—rarely do you need to look past your dry fly box here.
🐟 Target Species & Behavior
Westslope Cutthroat Trout
These are the stars of the Lochsa. They are opportunistic feeders because the river is nutrient-poor.
- Behavior: They are known for their aggression. Unlike picky rainbows in tailwaters, Lochsa Cutthroats will often move several feet to smash a dry fly.
- Holding Water: Look for "soft" spots in the chaos. They hold behind large boulders, in the seams where fast and slow water meet, and in the tailouts of deep pools.
Steelhead
The Lochsa receives a run of "B-run" Clearwater Steelhead, known for their impressive size (often exceeding 30 inches).
- Behavior: These fish are traveling through on their way to spawning grounds. They are less focused on feeding and more on territorial aggression or instinct.
- Holding Water: They prefer the "traveling lanes"—deeper walking-speed water and the heads of large pools where the water oxygenates.
📅 Best Times to Fish
Summer (July – August)
- The Window: Fishing usually begins in early July once the spring runoff subsides.
- Conditions: This is the prime dry fly season. As the water drops and clears, the fish become hyper-active.
- Time of Day: Early morning and late evening are best during heat waves, but because the water stays cold, the "midday heat" can actually trigger great terrestrial activity.
Fall (September – October)
- The Window: This is "Trophy Season."
- Conditions: The water is at its lowest and clearest. The big Cutthroats congregate in deeper holes, and the first of the Steelhead begin to arrive.
- Prime Window: The October Caddis hatch (late Sept/Oct) is legendary. Large, orange dries will bring up the biggest trout in the river.
🪰 Recommended Flies & Techniques
Dry Fly Fishing (The Primary Method)
The Lochsa is a dry-fly river first.
- Patterns:
- Attractors: Royal Wulff, Purple Haze (size 12-16).
- Stoneflies: Golden Stones and Chubby Chernobyls (size 8-12).
- Terrestrials: Morrish Hoppers and Amy’s Ants in August.
- October Caddis: Orange Stimulators or specialized October Caddis patterns (size 8-10).
- Technique: Use a Reach Cast. The complex currents will create drag instantly; an aerial mend is essential to keep that fly floating naturally through the pocket.
Nymphing
Use this when the sun is high or in the deep winter/spring holes.
- Patterns: Pat’s Rubber Legs (Brown/Black), Prince Nymphs, and Perdigons for fast-sinking action.
- Technique: "High-sticking" through the pockets. Keep as much fly line off the water as possible to avoid the conflicting surface currents.
Steelhead Techniques
- Patterns: Prom Dress, Green Butt Skunk, or heavy Intruders in blue/black or purple.
- Technique: Swinging flies with a Spey rod or heavy switch rod is the traditional and most rewarding method here. Focus on the lower sections of the river.
💡 Pro Tips & Local Knowledge
- The "Lochsa Lean": The biggest Cutthroats often sit much closer to the bank than you think. Before wading into a run, fish the "inside" seam right at your feet.
- Cover Water: Don't spend an hour in one hole. The Lochsa rewards the mobile angler. Hit the high-percentage pockets, catch the 2-3 aggressive fish, and move 20 yards upstream.
- Highway 12 Safety: While the road provides access, it is a major corridor for logging trucks. Use the pullouts and be extremely careful when walking the shoulder.
- The "Lower" vs "Upper": The lower river (near Lowell) is larger and better for Steelhead. The upper river (near Powell) is tighter, more technical, and excellent for high-summer Cutthroat action.
⚠️ Important Information
- Regulations: The Lochsa is generally Catch and Release only for trout. You must use barbless hooks. Always check the current Idaho Fish and Game seasons and rules, as Steelhead seasons can change based on return numbers.
- Wading Safety: The rocks in the Lochsa are notorious for being "bowling balls covered in snot." Felt soles or studs, and a wading staff, are highly recommended.
- Wildlife: This is serious Grizzly and Black Bear country. Carry bear spray and know how to use it.
- Connectivity: There is zero cell service for most of the corridor. Download your maps for offline use and let someone know your plan.
Bug Hatches & Matching Flies
| Hatch | Type | Peak months | Time of day | Hook sizes | Matching flies |
|---|---|---|---|---|---|
| Salmonfly Pteronarcys californica | stonefly | June | All Day | #4-8 | Sofa Pillow #6-8, Rogue Foam Stone #4-8, Pat's Rubber Legs #4-8 |
| Golden Stonefly Hesperoperla pacifica | stonefly | June, July | Morning/Afternoon | #8-12 | Chubby Chernobyl #8-12, Golden Stimulator #10-12, 20-Incher Stone #8-12 |
| Green Drake Drunella doddsi | mayfly | June, July | Afternoon | #10-12 | Hairwing Green Drake #10-12, Quigley Cripple #10-12, Dorset Drake #12 |
| Pale Morning Dun (PMD) Ephemerella spp. | mayfly | July, August | Late Morning/Early Afternoon | #14-18 | Sparkle Dun #14-18, Pheasant Tail Nymph #14-18, PMD Emerger #16-18 |
| October Caddis Dicosmoecus gilvipes | caddis | September, October | Afternoon/Evening | #8-10 | Orange Stimulator #8-10, October Caddis Pupa #8-10, Morrish October Caddis #8-10 |
| Skwala Stonefly Skwala americana | stonefly | March, April | Afternoon | #10-12 | Skwala Stone Dry #10-12, Bullet Skwala #12, Olive Girdled Bugger #10 |
| Blue Winged Olive (BWO) Baetis spp. | mayfly | April, May, September, October | Mid-day/Overcast | #18-22 | BWO Parachute #18-20, RS2 #20-22, Baetis Nymph #18-20 |
| Western Grannom Brachycentrus occidentalis | caddis | April, May | Afternoon | #14-16 | Peacock Caddis #14-16, Deep Sparkle Pupa #14-16, Elk Hair Caddis (Olive) #14-16 |
| Terrestrials Orthoptera / Formicidae | terrestrial | August, September | Mid-day | #10-16 | Dave's Hopper #10-12, Cinnamon Ant #14-16, Black Beetle #14-16 |