Wyoming ·
Lamar River Fly Fishing Report - May 31, 2026
LAMAR RIVER
ReportMAY 31 — JUN 7, 2026
🌊
Flow
—CFS
🌡️
Water Temp
—
☀️
Weather
34–66°F
Rain Showers
💧
Clarity
Clear
Check post-storm
The Lamar River is in full spring runoff with high, turbid flows — USGS gauge data is currently unavailable. Overnight rain showers (80% chance, low 36°F) continue through Sunday before a clearing trend Monday brings mostly sunny skies and a high near 66°F, offering the best dry fly window of the weekend.
What's Working — Hot Flies
Parachute - Blue Wing Olive #22
#22
Egan's CDC Rainbow Warrior #22
#22
Top Secret Baetis #16
#16
Egan's Silver Bullet - Baetis #14
#14
Olsen's Straggle Stone Brown Barbless #12
#12
Tungsten Pat's Rubber Legs - Tan & Brown #6
#6
Blowtorch - Hare's Ear #12
#12
Tungsten Rainbow Warrior - Extra Heavy #14
#14
Slush Egg Apricot #14
#14
Wiggly Worm (TBH) #8
#8
Coffey's CH Sparkle Minnow Sculpin #6
#6
Egan's Frenchie Chironomid #10
#10
Hatch Chart
| Insect | Size | Activity | Prime Time |
|---|---|---|---|
| Blue-Winged Olive (Baetis) | #18–22 | 🟢 Active | 11 AM – 4 PM, especially on overcast days |
| Midge / Chironomid | #20–24 | 🟢 Active | Morning & evening in slow backwaters |
| Early Golden Stonefly (nymph) | #10–14 | 🟡 Building subsurface | All day subsurface; adults not yet out |
| Pale Morning Dun | #16–18 | 🔴 Just emerging | Expected late May into June; watch for first sightings |
| Caddis (Little Brown / Miller) | #16–18 | 🔴 Not yet | Anticipated as flows drop and water warms in June |
Best Time Window
- Sunday 11 AM – 4 PM: Overcast skies trigger the best BWO/Baetis dry fly action along slow bank edges and eddies despite ongoing rain showers
- Sunday evening (after 5 PM): Midge activity picks up in calm backwaters as temperatures stabilize — fish chironomid and midge patterns in the slowest water you can find
- Monday 10 AM – 3 PM: Best overall window of the weekend — clearing skies, 66°F high, and light SW winds create ideal conditions for both nymphing and opportunistic dry fly fishing
Guide's Tip
From the benchWith the Lamar running high and turbid from snowmelt, abandon the main channel entirely and focus on inside bends, slack-water eddies, and the seam where clear bank water meets the turbid main current — that's where Yellowstone cutthroat stack up to intercept food without fighting heavy flows. Rig a 10–12 ft leader, weight aggressively to get your nymph to the bottom fast, and keep your indicator close to the bank with upstream mends to maintain a drag-free drift. Monday's clearing skies and 66°F high will be your best dry fly window of the weekend — watch for BWO spinners and emergers in the film between 11 AM and 4 PM along slower bank edges, and be ready to downsize to 5X–6X tippet when fish get selective. The Lamar Valley is prime grizzly and wolf country — always carry bear spray, make noise on approach, and handle every native Yellowstone cutthroat with wet hands for a quick, healthy release.
Main Species
Yellowstone Cutthroat Trout
Rainbow Trout
