Hatch Guide · Mayfly (Ephemerellidae)

Pale Morning Dun

The PMD is the dominant mayfly hatch of Western trout rivers, providing consistent surface activity from late spring through summer.

Peak months: MayJune · nowJulyAugust

Top fly patterns

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Month-by-month activity

Number of rivers where the Pale Morning Dun hatch is active each month.

Jan
Feb
Mar
Apr
21 rivers
May
32 rivers
Jun ●
32 rivers
Jul
32 rivers
Aug
14 rivers
Sep
4 rivers
Oct
Nov
Dec

Rivers where Pale Morning Dun hatches

Westfield River Active now
Massachusetts Active: May, Jun, Jul
Wild trout freestone river in the Berkshires. West Branch holds native brookies in upper reaches. St…
Ausable River Active now
New York Active: May, Jun, Jul
Classic Adirondack freestone river with wild brookies in upper reaches and browns and rainbows in th…
Gallatin River Active now
Montana Active: May, Jun, Jul
Classic freestone river paralleling Highway 191 through the canyon south of Bozeman. Wild fish in th…
Madison River Active now
Montana Active: Apr, May, Jun, Jul, Aug
One of Montana's legendary Blue Ribbon rivers. PMD, caddis, and salmonfly hatches make June and July…
Missouri River Active now
Montana Active: Apr, May, Jun, Jul, Aug
World-class tailwater below Holter Dam near Craig. Midge and BWO hatches year-round; PMD and trico d…
Blackfoot River Active now
Montana Active: May, Jun, Jul
Immortalized by Norman Maclean's A River Runs Through It. Recovered wild fishery with strong stonefl…
Big Hole River Active now
Montana Active: Apr, May, Jun, Jul, Aug
One of the last wild arctic grayling rivers in the lower 48. Blue Ribbon trout water with massive sa…
Yellowstone River Active now
Montana Active: Apr, May, Jun, Jul, Aug
The longest free-flowing river in the lower 48. Paradise Valley section near Livingston is prime Blu…
Bitterroot River Active now
Montana Active: May, Jun, Jul
Scenic freestone river in the Bitterroot Valley south of Missoula. Good caddis and PMD hatches. Nati…
Clark Fork River Active now
Montana Active: May, Jun, Jul
Recovering river through Missoula and western Montana. Bull trout present — handle with care. Good c…
Snake River Active now
Wyoming Active: May, Jun, Jul
Pure wild Snake River fine-spotted cutthroat trout in a spectacular Teton backdrop. Float-fishing th…
North Platte River Active now
Wyoming Active: Apr, May, Jun, Jul, Aug
The famous Miracle Mile below Seminoe Reservoir — cold tailwater holding large rainbows and browns. …
South Platte River Active now
Colorado Active: Apr, May, Jun, Jul, Aug
Gold Medal water through Cheesman Canyon and the Dream Stream above Eleven Mile Reservoir. Highly te…
Fryingpan River Active now
Colorado Active: Apr, May, Jun, Jul, Aug
World-class Gold Medal tailwater below Ruedi Reservoir near Basalt. Massive midge and PMD hatches. M…
Arkansas River Active now
Colorado Active: May, Jun, Jul
Gold Medal freestone river through the Arkansas Valley. Good caddis and PMD hatches. Wade fishing be…
Roaring Fork River Active now
Colorado Active: May, Jun, Jul
Gold Medal freestone and tailwater water through Aspen and down to Glenwood Springs. Strong PMD, cad…
Blue River Active now
Colorado Active: Apr, May, Jun, Jul, Aug
Gold Medal tailwater below Dillon Reservoir in Silverthorne. Heavily fished but holds large fish. Mi…
Cache la Poudre River Active now
Colorado Active: May, Jun, Jul
Colorado's only federally designated Wild and Scenic River. Freestone character through Poudre Canyo…
Henry's Fork Active now
Idaho Active: Apr, May, Jun, Jul, Aug, Sep
The Railroad Ranch reach through Harriman State Park is among the world's greatest dry-fly fisheries…
Silver Creek Active now
Idaho Active: Apr, May, Jun, Jul, Aug, Sep
Spring creek near Hemingway's Sun Valley. Crystal clear, spring-fed water with massive, selective tr…
South Fork Boise River Active now
Idaho Active: Apr, May, Jun, Jul, Aug
Cold tailwater below Anderson Ranch Dam. Strong midge and PMD hatches. Bull trout present — handle c…
Salmon River Active now
Idaho Active: May, Jun, Jul
The River of No Return — a wilderness canyon river through central Idaho. Wild steelhead and chinook…
Deschutes River Active now
Oregon Active: Apr, May, Jun, Jul
Oregon's crown jewel. Wild redsides and summer steelhead in a dramatic canyon. Salmonfly hatch in la…
Rogue River Active now
Oregon Active: Apr, May, Jun, Jul
Wild and Scenic River with famous steelhead and salmon runs. Spring Chinook and summer steelhead att…
McKenzie River Active now
Oregon Active: Apr, May, Jun, Jul
Home of the McKenzie River drift boat design. Gin-clear spring-fed water with wild rainbows. Skwala …
Metolius River Active now
Oregon Active: Apr, May, Jun, Jul
Spring-fed river emerging fully formed from the base of Black Butte. Catch-and-release artificial on…
Yakima River Active now
Washington Active: Apr, May, Jun, Jul
Washington's premier trout river — Blue Ribbon water through the canyon below Cle Elum. Skwala hatch…
Green River Active now
Utah Active: Apr, May, Jun, Jul, Aug
World-class tailwater below Flaming Gorge Dam. Sections A, B, and C offer different water types. Pro…
Provo River Active now
Utah Active: Apr, May, Jun, Jul, Aug
Gold Medal tailwater from Jordanelle Reservoir through Provo Canyon. Midge and BWO year-round; PMD a…
San Juan River Active now
New Mexico Active: Apr, May, Jun, Jul, Aug
Year-round Gold Medal tailwater with consistent flows below Navajo Dam. The Texas Hole no-kill stret…
Hat Creek Active now
California Active: Apr, May, Jun, Jul, Sep
Spring-fed wild trout fishery below PG&E powerhouse. California Wild Trout Program water with artifi…
Fall River Active now
California Active: Apr, May, Jun, Jul, Sep
Boat-access-only spring creek in the Fall River Valley. Flat, clear water with massive, selective wi…

How to fish the Pale Morning Dun

Match the specific emergence stage: nymph with a Rainbow Warrior in the morning, switch to Comparaduns as duns come off midday, then fish Rusty Spinners in the evening film. Size 16–18. Fine tippet (6X) on flat water is non-negotiable.

Frequently asked

When does the Pale Morning Dun hatch?

Peak emergence: May, June, July, August. Timing varies by elevation, latitude, and water temperature.

What flies match the Pale Morning Dun hatch?

Top patterns: Pale Morning Dun (size 16-18); Pale Evening Dun (size 14-18); Rainbow Warrior (size 16-20).

What rivers have a good Pale Morning Dun hatch?

Pale Morning Dun hatches are documented on 32 rivers including: Westfield River, Ausable River, Gallatin River, Madison River, Missouri River and 27 more.

How do I fish the Pale Morning Dun hatch?

Match the specific emergence stage: nymph with a Rainbow Warrior in the morning, switch to Comparaduns as duns come off midday, then fish Rusty Spinners in the evening film. Size 16–18. Fine tippet (6X) on flat water is non-negotiable.

What is the Pale Morning Dun?

The PMD is the dominant mayfly hatch of Western trout rivers, providing consistent surface activity from late spring through summer. Family: Mayfly (Ephemerellidae).

Related

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