North Platte River Wyoming Hatch Chart

Central Wyoming, flowing north and east from the Sierra Madre range through Saratoga and Casper before turning south toward Nebraska. The North Platte River system contains some of the finest tailwater trout fisheries in the Rocky Mountain West - particularly the legendary Grey Reef and Miracle Mile sections below Pathfinder and Seminoe Reservoirs near Casper. These tailwater reaches produce trophy-class brown and rainbow trout in numbers that rival anything in Wyoming or the surrounding states.

Check current Wyoming Game and Fish Department regulations before you go. The North Platte system has special regulations that vary significantly by section - Grey Reef, Miracle Mile, and the Fremont Canyon sections each have their own rules regarding methods, seasons, and size limits. Regulations change - verify current rules for your specific section before every trip.

Shop by type: dry flies, nymphs, Euro nymphs, hoppers and terrestrials, streamers.

The river

The North Platte's three most celebrated tailwater sections each have a distinct character. Grey Reef, immediately below Alcova Reservoir dam, is wide, wadeable, and technical - a long flat reach with massive fish counts and selective trout that demand precise nymph presentations and fine tippets. The Miracle Mile between Pathfinder and Alcova Reservoirs is a true year-round trophy fishery - remote, wild, and capable of producing brown and rainbow trout exceeding 20 inches on any given day. Fremont Canyon below Pathfinder Dam is the most dramatic setting - a narrow basalt canyon with deep pools and exceptional streamer fishing for large browns.

Brown trout are the signature species across all three sections, with rainbow trout sharing the system in significant numbers. The tailwater character of these reaches means stable, cold flows year-round - these rivers are fishable in every month and reward the angler willing to make the drive to Casper-area Wyoming in the off season when pressure is minimal and large fish are accessible.

The North Platte is a nymph fisherman's river first. The biomass of aquatic insects - midges, PMDs, BWO, caddis - is extraordinary and fish feed subsurface on nymphs and pupae throughout the year. Dry-fly fishing is excellent during the spring and fall BWO hatches and through the hopper season, but the angler who puts away the nymphs entirely will leave fish unfished on the North Platte.

Year at a glance - Grey Reef and Miracle Mile

Month	Primary hatches	Also carry	Typical sizes
Jan	Midges	Small nymphs, streamers	20-26
Feb	Midges, BWO	Small nymphs, streamers	18-24
Mar	BWO, midges	Early caddis, streamers	BWO 16-20, midge 20-24
Apr	BWO, caddis, midges	Streamers, March Brown	BWO 16-20, caddis 14-16
May	Caddis, PMD, BWO	Yellow sally, streamers	Caddis 14-16, PMD 16-18
Jun	PMD, caddis, yellow sally	Golden stone, hoppers start	PMD 16-18, caddis 14-16
Jul	PMD, hoppers, caddis	Ants, yellow sally, streamers	PMD 16-18, hopper 8-12
Aug	Hoppers, PMD, caddis	Ants, beetles, trico	Hopper 8-12, PMD 16-18
Sep	BWO, hoppers, caddis	Mahogany dun, streamers	BWO 16-20, hopper 8-12
Oct	BWO, midges	Streamers, mahogany dun	BWO 16-20, midge 20-24
Nov	Midges, BWO	Small nymphs, streamers	20-24
Dec	Midges	Small nymphs, streamers	20-26

January

The Grey Reef and Miracle Mile fish year-round and January is the midge and streamer season. Stable tailwater temperatures keep fish active through the coldest Wyoming weather - the fish do not slow down even when the air temperature drops well below freezing. Midge larvae and pupae on a tight-line Euro rig is the most consistent winter approach. Streamer fishing for large browns in the deeper Fremont Canyon pools is outstanding in January with virtually no competition. Bundle up and fish - the North Platte in January is one of Wyoming's best-kept secrets.

Midges - 20-26. Red zebra midge and small Euro nymphs subsurface. Midge cluster dry when fish are dimpling in flat tailouts.
Streamers for large browns in Fremont Canyon and the deeper Miracle Mile pools - streamers year-round.

February

BWO begin on overcast afternoons in February at Grey Reef - the tailwater stability makes this one of the earlier BWO sections in Wyoming. Midges continue throughout. Streamers remain productive in the canyon sections. February on the North Platte with rising fish on a warm afternoon and no other anglers present is a genuinely exceptional experience.

BWO - 18-22 on overcast afternoons. Parachute BWO when fish are rising.
Midges throughout. Red zebra midge subsurface.
Streamers in the canyon sections. Streamers.

March

BWO hatches strengthen significantly through March at Grey Reef and the Miracle Mile. Early caddis begin on warmer afternoons by late month. Midges continue as the subsurface anchor. March is one of the finest months on the North Platte - dense BWO hatches, large rising fish, and light pressure before the spring crowd arrives. The Grey Reef flats in March with BWO hatching and 20-inch browns rising is world-class dry-fly fishing.

BWO - 16-20. Parachute BWO and CDC Baetis emerger on overcast afternoons.
Midges throughout. Red zebra midge subsurface.
Late March: first caddis - 14-16 on warm afternoons.
Streamers in the canyon for pre-spawn browns. Streamers.

April

Caddis build through April and overlap with continuing BWO hatches. The tailwater character of Grey Reef and the Miracle Mile means April is reliably fishable when nearby freestone streams are blown out from snowmelt. March Browns appear on the broader sections. Evening caddis hatches in April can be outstanding. Spring is prime time on the North Platte - excellent hatches, good flows, and fish in prime condition before summer pressure arrives.

BWO - 16-20. Parachute BWO on overcast days.
Caddis - 14-16. Elk hair caddis afternoons and evenings.
Midges throughout. Red zebra midge subsurface.
March Brown - 12-14 on the broader Grey Reef flats.

May

Prime season opens in May. Caddis hatches peak and PMDs begin on the Grey Reef flats and Miracle Mile. Yellow sallies in the riffles. BWO continue on overcast days. May is one of the best months on the North Platte - full hatch sequence underway, excellent fish activity, and lighter pressure than the summer peak. The combination of evening caddis and morning PMDs with large browns and rainbows feeding throughout makes May a must-visit month.

Caddis - 14-16 evenings. Elk hair.
PMD - 16-18. Pale Morning Dun mornings on the flatter sections.
BWO on overcast days. Parachute BWO.
Yellow sally - 14-16 in the riffles on warm afternoons.
Nymphs subsurface throughout from nymphs.

June

Peak season at Grey Reef and the Miracle Mile. PMDs are the dominant morning hatch and the Grey Reef flats in a June PMD hatch with large fish rising across the flat is one of Wyoming's finest fly fishing experiences. Caddis evenings remain strong. Yellow sallies in the riffles. Hoppers begin along the sage banks by late June. The North Platte sees its heaviest guide traffic in June and July - fish early morning and late evening for the best fish-to-angler conditions.

PMD - 16-18. Pale Morning Dun mornings on the Grey Reef flats.
Caddis - 14-16 evenings. Elk hair.
Yellow sally - 14-16 in the riffles.
Late June: first hoppers - hoppers and terrestrials along the sage banks.

July

PMDs continue and hoppers build through July along the sage and grassy banks of the Miracle Mile and Grey Reef. Caddis evenings remain reliable. Ants and beetles midday. The tailwater temperatures keep fish active through the warmest July days - a significant advantage over nearby freestone rivers. Fish the mornings for PMDs and the afternoons for hoppers before the evening caddis hatch begins. July is busy but the fish are there and feeding.

PMD - 16-18. Pale Morning Dun mornings.
Hoppers - 8-12. Hoppers and terrestrials along the sage banks. Hopper-dropper with a nymph dropper.
Caddis - 14-16 evenings. Elk hair.
Yellow sally - 14-16 in the riffles.
Ants and beetles midday from hoppers and terrestrials.

August

Hopper season peaks in August and the Miracle Mile is exceptional terrestrial water - the wide sage flats along both banks concentrate hoppers and the large browns and rainbows respond aggressively. PMDs continue in the mornings. Caddis evenings. Trico spinner falls on the flatter Grey Reef sections by mid-month. Ants and beetles midday. August hopper fishing on the Miracle Mile is one of the finest terrestrial experiences in Wyoming.

Hoppers - 8-12. Hoppers and terrestrials along the sage and grass banks. Hopper-dropper with a nymph.
PMD - 16-18 mornings. Pale Morning Dun.
Caddis - 14-16 evenings. Elk hair.
Trico - 20-24 early morning on the Grey Reef flats. Fine tippet.
Ants and beetles midday. Hoppers and terrestrials.

September

September rivals March as the finest month on the North Platte. Hoppers continue through mid-month. BWO return strongly with the cooling temperatures - the fall olive hatches on the Grey Reef flats produce outstanding afternoon dry-fly fishing with large fish rising selectively. Mahogany duns add variety on overcast days. Crowds drop sharply after Labor Day. The combination of hopper mornings, BWO afternoons, and streamers for pre-spawn browns makes September the most complete month on the North Platte.

Hoppers through mid-September. Hoppers and terrestrials.
BWO - 16-20. Parachute BWO and CDC Baetis emerger on overcast afternoons.
Mahogany dun - 14-16 on overcast afternoons.
Caddis evenings through mid-September. Elk hair.
Streamers for pre-spawn browns - streamers in the canyon and deeper Miracle Mile pools.

October

Outstanding fall fishing. BWO hatches strengthen through October on the Grey Reef flats - dense afternoon hatches with very few other anglers. Streamers produce the largest browns of the year as pre-spawn aggression peaks in October and November. Mahogany duns on overcast days. Midges reassert themselves as temperatures drop. October on the North Platte is one of the finest fall fly fishing experiences in Wyoming - large fish, excellent hatches, and virtually no pressure compared to summer.

BWO - 16-20. The dominant hatch. Parachute BWO.
Mahogany dun - 14-16 on overcast days.
Midges - 20-24 picking back up. Red zebra midge.
Streamers for trophy pre-spawn browns - streamers in Fremont Canyon and the deeper Miracle Mile runs.

November

BWO and midges as the season winds toward winter. Streamers remain the best option for the largest fish as brown trout pre-spawn and spawn activity continues. Very few anglers. The North Platte in November with BWO hatching and large browns in the shallows is exceptional fishing for the angler willing to make the drive to central Wyoming in cold weather.

BWO - 16-20 on overcast afternoons. Parachute BWO.
Midges - 20-24. Red zebra midge subsurface.
Streamers for large browns - streamers in the canyon and deep runs.

December

Back to the winter midge and streamer program. The tailwater sections fish year-round - December on the North Platte with a streamer rod for post-spawn browns and active winter fish is a unique and rewarding experience. Complete solitude, stable flows, and active fish in world-class water. Focus on the slower runs adjacent to the main current and the deep canyon pools.

Midges - 20-26. Red zebra midge and small nymphs subsurface. Midge cluster dry when fish are dimpling.
BWO on overcast afternoons. Parachute BWO.
Streamers for large browns year-round - streamers in Fremont Canyon and the deep Miracle Mile pools.

A western dry and nymph assortment covers the core season. Add a dedicated streamer selection for year-round use - the North Platte's trophy browns respond to streamers in every month. The Grey Reef, Miracle Mile, and Fremont Canyon sections together make the North Platte one of the most diverse and productive tailwater systems in the Rocky Mountain West, capable of producing world-class fishing in every season for the angler who makes the commitment to fish it properly.