Hatch Guide · Ants, beetles, hoppers, crickets

Terrestrials

Terrestrial insects fall or blow into rivers all summer and are a critical food source, especially in late July and August.

Peak months: JulyAugustSeptember

Top fly patterns

1
2
Size 6-10 · streamer
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Month-by-month activity

Number of rivers where the Terrestrials hatch is active each month.

Jan
Feb
Mar
Apr
May
Jun ●
22 rivers
Jul
48 rivers
Aug
48 rivers
Sep
10 rivers
Oct
Nov
Dec

Rivers where Terrestrials hatches

Farmington River
Connecticut Active: Jul, Aug, Sep
Trout Management Area below Riverton — catch-and-release artificial-only year-round. Lower river sto…
Housatonic River
Connecticut Active: Jul, Aug, Sep
Catch-and-release TMA between Cornwall Bridge and Boardman Bridge. Hatches: caddis, Hendricksons, su…
Salmon River
Connecticut Active: Jul, Aug, Sep
Atlantic Salmon Broodstock area — special regs apply. Heavily stocked sections.
Willimantic River
Connecticut Active: Jul, Aug
TMA section near Willimantic. Spring and fall stocking.
Deerfield River
Massachusetts Active: Jul, Aug, Sep
Cold tailwater below Fife Brook Dam (Florida, MA) plus the Mohawk Trail water. Dam releases drive fl…
Westfield River Active now
Massachusetts Active: Jun, Jul, Aug
Wild trout freestone river in the Berkshires. West Branch holds native brookies in upper reaches. St…
Battenkill River
Vermont Active: Jul, Aug, Sep
Classic wild brown and brook trout river — no stocking, technical fish, clear water. Cooler than the…
Upper Delaware River
Pennsylvania / New York Active: Jul, Aug, Sep
Big tailwater-influenced system (West and East Branches plus the main stem) holding wild rainbows an…
Beaverkill River
New York Active: Jul, Aug, Sep
The birthplace of American dry-fly fishing. Classic Catskill freestone water with Quill Gordon, Hend…
Ausable River Active now
New York Active: Jun, Jul, Aug
Classic Adirondack freestone river with wild brookies in upper reaches and browns and rainbows in th…
Esopus Creek
New York Active: Jul, Aug
NYC watershed tailwater — Tunnel Portal releases cold water from the Schoharie Reservoir, keeping te…
Penns Creek
Pennsylvania Active: Jul, Aug
Limestone-fed wild trout stream famous for its Green Drake hatch in late May. Catch-and-release sect…
Brodhead Creek
Pennsylvania Active: Jul, Aug
Historic Pocono trout stream. Wild and stocked fish. Good access throughout. Classic Hendrickson and…
Gallatin River Active now
Montana Active: Jun, Jul, Aug
Classic freestone river paralleling Highway 191 through the canyon south of Bozeman. Wild fish in th…
Madison River Active now
Montana Active: Jun, Jul, Aug, Sep
One of Montana's legendary Blue Ribbon rivers. PMD, caddis, and salmonfly hatches make June and July…
Missouri River
Montana Active: 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: Jun, Jul, Aug
Immortalized by Norman Maclean's A River Runs Through It. Recovered wild fishery with strong stonefl…
Big Hole River Active now
Montana Active: Jun, Jul, Aug, Sep
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: Jun, Jul, Aug, Sep
The longest free-flowing river in the lower 48. Paradise Valley section near Livingston is prime Blu…
Bitterroot River Active now
Montana Active: Jun, Jul, Aug
Scenic freestone river in the Bitterroot Valley south of Missoula. Good caddis and PMD hatches. Nati…
Clark Fork River Active now
Montana Active: Jun, Jul, Aug
Recovering river through Missoula and western Montana. Bull trout present — handle with care. Good c…
Snake River Active now
Wyoming Active: Jun, Jul, Aug
Pure wild Snake River fine-spotted cutthroat trout in a spectacular Teton backdrop. Float-fishing th…
North Platte River
Wyoming Active: Jul, Aug
The famous Miracle Mile below Seminoe Reservoir — cold tailwater holding large rainbows and browns. …
South Platte River
Colorado Active: Jul, Aug
Gold Medal water through Cheesman Canyon and the Dream Stream above Eleven Mile Reservoir. Highly te…
Fryingpan River
Colorado Active: Jul, Aug
World-class Gold Medal tailwater below Ruedi Reservoir near Basalt. Massive midge and PMD hatches. M…
Arkansas River Active now
Colorado Active: Jun, Jul, Aug
Gold Medal freestone river through the Arkansas Valley. Good caddis and PMD hatches. Wade fishing be…
Roaring Fork River Active now
Colorado Active: Jun, Jul, Aug
Gold Medal freestone and tailwater water through Aspen and down to Glenwood Springs. Strong PMD, cad…
Blue River
Colorado Active: 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: Jun, Jul, Aug
Colorado's only federally designated Wild and Scenic River. Freestone character through Poudre Canyo…
Henry's Fork
Idaho Active: Jul, Aug
The Railroad Ranch reach through Harriman State Park is among the world's greatest dry-fly fisheries…
Silver Creek
Idaho Active: Jul, Aug
Spring creek near Hemingway's Sun Valley. Crystal clear, spring-fed water with massive, selective tr…
South Fork Boise River
Idaho Active: Jul, Aug
Cold tailwater below Anderson Ranch Dam. Strong midge and PMD hatches. Bull trout present — handle c…
Salmon River Active now
Idaho Active: Jun, Jul, Aug
The River of No Return — a wilderness canyon river through central Idaho. Wild steelhead and chinook…
Deschutes River Active now
Oregon Active: Jun, Jul, Aug
Oregon's crown jewel. Wild redsides and summer steelhead in a dramatic canyon. Salmonfly hatch in la…
Rogue River Active now
Oregon Active: Jun, Jul, Aug
Wild and Scenic River with famous steelhead and salmon runs. Spring Chinook and summer steelhead att…
McKenzie River Active now
Oregon Active: Jun, Jul, Aug
Home of the McKenzie River drift boat design. Gin-clear spring-fed water with wild rainbows. Skwala …
Metolius River Active now
Oregon Active: Jun, Jul, Aug
Spring-fed river emerging fully formed from the base of Black Butte. Catch-and-release artificial on…
Yakima River Active now
Washington Active: Jun, Jul, Aug
Washington's premier trout river — Blue Ribbon water through the canyon below Cle Elum. Skwala hatch…
Green River
Utah Active: Jul, Aug
World-class tailwater below Flaming Gorge Dam. Sections A, B, and C offer different water types. Pro…
Provo River
Utah Active: Jul, Aug
Gold Medal tailwater from Jordanelle Reservoir through Provo Canyon. Midge and BWO year-round; PMD a…
San Juan River
New Mexico Active: Jul, Aug
Year-round Gold Medal tailwater with consistent flows below Navajo Dam. The Texas Hole no-kill stret…
Au Sable River
Michigan Active: Jul, Aug
Michigan's most famous trout river — spring-fed, clear water through northern Michigan pines. The He…
Pere Marquette River
Michigan Active: Jul, Aug
Blue Ribbon wild trout and steelhead river through northern Michigan. Spring steelhead and fall chin…
Watauga River Active now
Tennessee Active: Jun, Jul, Aug
Cold tailwater below Watauga Dam. Year-round fishery with strong sulphur, caddis, and yellow sally h…
Davidson River Active now
North Carolina Active: Jun, Jul, Aug
Gem of the Southern Appalachians in Pisgah National Forest. Wild trout in clear mountain water. Hatc…
Rose River Active now
Virginia Active: Jun, Jul, Aug
Remote wild trout stream in Shenandoah National Park foothills. Native brook trout in upper reaches,…
Hat Creek
California Active: Jul, Aug
Spring-fed wild trout fishery below PG&E powerhouse. California Wild Trout Program water with artifi…
Fall River
California Active: Jul, Aug
Boat-access-only spring creek in the Fall River Valley. Flat, clear water with massive, selective wi…

How to fish the Terrestrials

Fish a hopper pattern tight to the bank and let it sit. Ants in size 14–20 fished flush in the film are deadly on educated fish.

Frequently asked

When does the Terrestrials hatch?

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

What flies match the Terrestrials hatch?

Top patterns: Dave's Hopper (size 8-12); Spruce Moth (size 6-10).

What rivers have a good Terrestrials hatch?

Terrestrials hatches are documented on 48 rivers including: Farmington River, Housatonic River, Salmon River, Willimantic River, Deerfield River and 43 more.

How do I fish the Terrestrials hatch?

Fish a hopper pattern tight to the bank and let it sit. Ants in size 14–20 fished flush in the film are deadly on educated fish.

What is the Terrestrials?

Terrestrial insects fall or blow into rivers all summer and are a critical food source, especially in late July and August. Family: Ants, beetles, hoppers, crickets.

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