Grey Reef
Fishable
Flow500 CFS
Trendstable
Clarityrain-stained downstream; cleanest water is up near the dam
Temp62-65°F
Sparkle Wing RS2 #18Poxyback PMD #18Sparkle Worm Red #10Pine Squirrel Leech #10
Miracle Mile Fishing Report: North Platte River Flows & Hatches
WY
intermediate
Quick Reference
| What | When | Key Numbers |
|---|---|---|
| Grey Reef fishing | Year-round (spring best for numbers) | 500-1,500 CFS ideal; 3,500+ trout/mile (WGFD) |
| Miracle Mile fishing | Year-round (spring rainbows, fall browns) | 400-1,200 CFS ideal wading; 3,200+ trout/mile |
| Guided float trips | Book by February for spring | $550-700/day (1-2 anglers) |
| Fall trophy browns | Mid-October through November | 20-30" spawners; streamers and egg patterns |
| Fly shop | Platte River Fly Shop | 7400 State Hwy 220, Casper, WY |
| Regulations | Single-point barbless hooks required (2026) | Artificial flies/lures only at Grey Reef |
Sections of the North Platte
Two very different fisheries share this river, and the one you should pick depends on whether you have a boat.
- Miracle Mile: The wade fishery. Roughly 5.5 miles of steeper, structured water between Kortes Dam and Pathfinder Reservoir, most of it on public land, 50 miles from Casper at the end of a dirt road. Covered in full on this page.
- Grey Reef: The float fishery. A 40-mile tailwater below Gray Reef Dam, 30 miles from Casper on pavement, with limited public bank access and a dam release calendar that drives the fishing. It has its own dedicated guide covering flows, access areas, float stretches, and 2026 regulations.
FISHABLE
Stale (13+ days)
Settled at 500 CFS after the 2,200-2,300 CFS irrigation peak in mid-July. Recent rain pushed color through the system and it gets dirtier downstream, so the water near the dam is fishing best. A voluntary hoot owl closure runs from Lusby down to the Dave Johnson power plant: no fishing past noon in that reach. The full Grey Reef report, release schedule, and fly list live on the dedicated Grey Reef guide.
Miracle Mile
Fishable
Flow500-540 CFS
Trendfalling
Clarity2-3 feet visibility per Grey Reef Anglers; rain may have added some color
Temp64°F (warmest in afternoon, coolest near dam)
Orange Scud #14-16Rock Worm #12San Juan Worm (red beaded) #10Squirmy Worm #10
🎣 TACTICS RIGHT NOWThermal management is the defining factor for late August. Miracle Mile is at 500 CFS with water at 64°F per Grey Reef Anglers, warming through the afternoon, so fish near the dam where it stays coolest. Tricos dominate the early morning, caddis carry the day, and PMDs and Yellow Sallies are still bringing fish up. Go subsurface: lead with Orange Scuds, Rock Worms, beaded red San Juan Worms, and simple leeches, with smaller Trico, caddis, or PMD droppers. No floating upstream of the Miracle Mile Bridge in 2026. When water hits 65°F, minimize handling and keep fish wet. Carry a stream thermometer, and bring a 7-weight for the wind.
Dry Fly
Drowned Trico Spinner #20 at first lightElk Hair Caddis #14-16 (caddis leading the charge per Crazy RainbowAug 25)PMD Comparadun #16Yellow Sally #14-16Parachute Adams #16-18BWO Parachute #18-20 on overcast daysDave's Hopper #10-12
Nymph
Orange Scud #14-16Rock Worm #12San Juan Worm (red beaded) #10Squirmy Worm #10Thin Mint #16-18Red Larva #14-16Pat's Rubber Legs #6-8 (brown/grey/chocolate)Pine Squirrel Leech #8-10Pheasant Tail #16-18Caddis Nymph #16. Subsurface is the most effective approach on the Mile per Crazy Rainbow (Aug 25).
Streamer
Pine Squirrel Leech #8-10simple leeches #8-10Pine Squirrel Leech Craw #8UV Leech #10Woolly Bugger #6-8 (olive/black). Streamers are moving big fish in low light.
FORECASTMiracle Mile is holding near 500 CFS with 2-3 feet of visibility and should stay close to base flow through September as irrigation demand eases. Water temps near 64°F make early morning and evening the productive windows. Caddis and Tricos are the surface story, with PMDs past peak. Expect brown trout to start moving by late September and streamer fishing to improve through October into November, the best trophy window of the year. Check road conditions before the drive, because the dirt access road turns impassable when wet. North Platte Lodge no longer sells fishing licenses, so buy before you arrive.
Overview
The North Platte River in central Wyoming holds two of the most productive tailwater fisheries in the Rocky Mountain West. The Miracle Mile, a 5.5-to-8-mile stretch between Kortes Dam and Pathfinder Reservoir, and Grey Reef, the 40-mile tailwater below Grey Reef Dam south of Casper, consistently rank among the top trout waters in the lower 48.
These are not scenery-first rivers. The landscape is high desert: sagebrush flats, sparse cottonwoods, and wind that will test your casting stroke. What they lack in postcard beauty they make up for in sheer biomass. Wyoming Game and Fish Department electrofishing surveys show 3,200 trout per mile at the Miracle Mile and up to 8,000 per mile in the upper Grey Reef. Fish average 16 to 20 inches, with legitimate shots at 10-pounders throughout the year.
Both fisheries owe their productivity to dam-controlled releases that keep water temperatures stable and nutrient-rich. Cold, oxygenated water from deep reservoir outlets creates ideal growing conditions for rainbow and brown trout, producing the kind of fish densities that draw anglers from across the country.
The high desert terrain surrounding the North Platte: sagebrush, rolling hills, and wind
Location and Access
The Miracle Mile and Grey Reef sit roughly 35 to 50 miles southwest of Casper along Wyoming Highway 220. Casper is the nearest city with full services, including fly shops, lodging, and restaurants.
Getting There
- From Casper: Take Hwy 220 south. Grey Reef Dam access is about 30 miles; Miracle Mile is 50 miles.
- From I-80 (Rawlins/Sinclair): Take the Seminoe/Kortes Road north for roughly 40 miles to reach the Miracle Mile.
- Nearest airports: Casper-Natrona County International (CPR). Denver International (DEN) is about 4.5 hours south.
Miracle Mile Access
The Miracle Mile sits between Kortes Dam and Pathfinder Reservoir. Two main parking areas provide access:
- Engstrom parking area (east side): Modern restrooms and camping
- Guthridge parking area (west side): Modern restrooms and camping
- 14-day camping limit applies at both areas
The access road is unpaved and notorious for becoming impassable when wet. Plan on bringing a vehicle with decent clearance, and check road conditions before committing to the drive. Cell service is nonexistent along most of the Mile. This is remote water, so bring everything you need.
Winter note: Wyoming Game and Fish does not plow the access road or parking areas in winter.
Grey Reef Access
Grey Reef has more boat ramps but less walkable bank than its reputation suggests. Public foot access in the famous upper river is concentrated at the Gray Reef Access Area at the dam, Trapper's Route, and the Lusby Public Access Area. Everything between them is private ranch land, where Wyoming law gives you the water but not the banks, so you float through rather than beach and wade.
Full detail: Grey Reef access areas, float stretches, and mileages.
Flow Windows
Both sections are tailwaters, meaning dam operators control flows. This is good news: you rarely deal with the unpredictable blowouts common on freestone rivers. The bad news is that flow changes can happen with little warning.
Grey Reef Flow Ranges
Grey Reef runs on a Bureau of Reclamation release calendar rather than on weather. Winter base flow sits near 500 CFS, a ten-day flushing cycle runs every March, and irrigation releases push the river to 2,000-3,000 CFS through most of the summer before dropping back near 500 CFS in October. Roughly 500 to 1,500 CFS is the range most anglers want.
Full detail: the Grey Reef release schedule and what each flow level means.
Miracle Mile Flow Ranges
| Flow (CFS) | Conditions |
|---|---|
| 400-800 | Low but fishable. Great wading water |
| 800-1,200 | Sweet spot. Both wading and floating work |
| 1,200-2,500 | Higher flows. Wading gets dicey; floats are productive |
| 2,500+ | Experienced guides only. Flows have historically hit 10,000+ CFS |
Track conditions in real time on RiverReports before making the drive, especially for the Miracle Mile. Burning an hour of dirt road only to find blown-out water is a hard lesson.
Key Sections
Miracle Mile
Despite the name, the Miracle Mile stretches roughly 5.5 miles from Kortes Dam downstream to the upper reaches of Pathfinder Reservoir. When Pathfinder is low, the fishable stretch can extend to 12 or even 15 miles.
Kortes Dam to the Bridge (2 miles): The steepest gradient on the Mile. Fast water pours through a canyon with pocket water, boulders, and defined pools. This is where the biggest fish tend to stack up, particularly near the dam outlet. Expect white-water conditions that require an experienced oarsman if you're floating.
Bridge to Chalk Bluffs (2 miles): The river widens into a series of large shelves followed by deep runs. Classic nymphing water. Wade anglers do well here because the structure is readable and the bank access is decent.
Chalk Bluffs to Pathfinder (variable): How much river is fishable here depends on the reservoir level. In low-water years, this section opens up miles of additional water. The terrain flattens into sagebrush prairie, and the river character changes to slower, deeper runs. Productivity varies season to season.
Grey Reef
The Grey Reef tailwater runs roughly 40 miles from Gray Reef Dam downstream through and past Casper, and the upper reaches hold the highest fish densities. The signature float is Gray Reef Dam to Lusby, about 8.4 miles and a full day with fishing. Below that, Lusby to Government Bridge, Government Bridge to Whitetail, Whitetail to Sechrist, and Bessemer Bend to Robertson Road each fish differently, with the Bessemer Bend run becoming a fall favorite as brown trout move up to spawn.
Full detail: the Grey Reef guide covers every float stretch with mileage, the three public wade areas, why the fish grow so large, and the current fishing report.
Seasons
Spring (March through May)
Spring is the marquee season for numbers. On the Grey Reef, Baetis hatches build from March through May, with dry fly windows on overcast afternoons.
On the Miracle Mile, spring means spawning rainbows. Fish in the 24-to-30-inch class run upstream from Pathfinder Reservoir starting in March. These are the biggest fish of the year, and they're focused on feeding heavily. Primary food sources include midges, leeches, scuds, and crayfish.
Spring also means wind. Persistent 15-to-25 mph gusts are the norm across this high desert country. Bring a 7-weight for wind management and a jacket that blocks it.
Important 2026 regulation: Two reaches of Grey Reef close April 1 through May 15 for the rainbow spawn, one just below the dam and one from Ledge Creek down to S Gulch. See the Grey Reef guide for exact boundaries.
A gravel ranch road through open range. The drive in to the Miracle Mile is this kind of road, so check conditions before committing to it
Summer (June through August)
Summer brings the best dry fly fishing of the year. The Miracle Mile's golden stonefly hatch (roughly Memorial Day through late June) produces explosive surface takes. Stimulators, Sofa Pillows, and Pat's Rubber Legs in sizes 6-10 all produce. After the stones taper off, caddis and PMD hatches carry the dry fly action into July.
On the Grey Reef, irrigation releases push flows to 2,000-3,000 CFS and most anglers switch to a boat. Overlapping PMD, Yellow Sally, Trico, and caddis hatches keep it interesting.
Fall (September through November)
Fall is trophy season for brown trout on both waters. Streamer fishing peaks in late October and the first two weeks of November. Bring a 7-weight and a box of oversized patterns: Circus Peanuts, Woolly Buggers, Bunny Leeches, and Sculpzillas in olive, black, and white. Egg patterns produce as browns and whitefish begin spawning.
On the Miracle Mile, brown trout from Pathfinder Reservoir make their annual spawning run upstream in November and December. The same aggressive streamer tactics apply.
Fall on the river: cottonwoods turn gold as brown trout move into spawning lies
Winter (December through February)
Both fisheries remain open year-round, and winter fishing can be surprisingly productive for anglers willing to deal with cold temperatures and short days.
Grey Reef sits at 500 CFS base flow, which concentrates fish and gives the best wading of the year. Midges hatch daily and the productive window runs roughly 11am to 3pm.
The Miracle Mile is more challenging in winter. The unpaved access road may be impassable, and the remote location means no bailout options if weather turns. Come prepared for self-sufficiency.
Winter tailwater conditions: cold air meets warmer dam releases, creating frost and mist along the banks
Hatches and Fly Patterns
Season-by-Season Recommendations
Winter (December through February)
- Midges: Zebra Midge #20-22, Mercury Midge #22, Griffith's Gnat #18-20, Top Secret Midge #20
- Subsurface: Leech patterns #6-8, Scud #14-16, San Juan Worm #10-12
- Streamers: Woolly Bugger #6-8 (olive, black), Bunny Leech #4-6
Spring (March through May)
- BWOs: Parachute BWO #18-20, WD-40 #20, Sparkle Dun #18
- Nymphs: Pheasant Tail #16-18, Copper John #14-16, Hare's Ear #14-16
- Miracle Mile specials: Orange Blossom Special #14-16, Platte River Spider #14, Egg Pattern #12-14
Summer (June through August)
- Stoneflies (Miracle Mile): Stimulator #8-10, Sofa Pillow #6-8, Pat's Rubber Legs #6-8, Double Bead Peacock Stone #8
- PMDs: Pheasant Tail #16, Sparkle Dun #16, Comparadun #16
- Caddis: Elk Hair Caddis #14-16, Goddard Caddis #14
- Tricos: Trico Spinner #20-22 (mornings)
- Yellow Sallies: Yellow Sally #14-16
Fall (September through November)
- Streamers: Circus Peanut #2-4, Sculpzilla #4-6, Woolly Bugger #4-8
- Egg patterns: Nuke Egg #10-12, Glo Bug #10-12
- BWOs: Same spring patterns; fall hatches often stronger than spring
- Midges: Rojo Midge #20-22, Zebra Midge #20
A well-stocked fly box for North Platte tailwaters: midges, BWOs, stonefly nymphs, and streamers
The Local Patterns
Two flies originated on the North Platte and still produce consistently:
- Platte River Spider (#14-16): A soft-hackle wet fly that imitates emergers. Deadly swung through riffles during BWO and midge activity.
- Platte River Special (#12-14): A flashy attractor nymph. Works as a lead fly in a two-nymph rig on both the Mile and the Reef.
- Orange Blossom Special (#14-16): An egg/attractor pattern that's a staple on the Miracle Mile, especially during rainbow spawning season.
Ask for these at any of the local fly shops. They'll steer you toward the right sizes and colors for current conditions.
Wading vs. Float Fishing
When to Wade
Wade fishing works best during lower flows (under 1,000 CFS) and on sections with public bank access. The Miracle Mile offers the most consistent wade fishing because much of it crosses public land. On the Grey Reef, wade access is limited to the public areas at the dam, Lusby, Government Bridge, and a few other access points.
Bring felt-soled boots or studded rubber soles. The cobble bottom gets slippery, and the cold tailwater temperatures mean a swim is more than just uncomfortable.
When to Float
Float trips are the most productive way to fish the Grey Reef. A drift boat covers 8 to 16 miles of water in a day, giving you access to holding lies that wade anglers never reach. Most guided trips use StealthCraft drift boats that seat two anglers and a guide.
On the Miracle Mile, floating is feasible but more technical. There are no formal boat ramps, and the upper section below Kortes Dam has genuine whitewater. This is not water for a novice oarsman. Grey Reef Anglers and other experienced guides know the put-in spots and how to handle high-water conditions.
Pronghorn are a common sight along the drive to the Miracle Mile through Wyoming's open range
Regulations (2026)
The Wyoming Game and Fish Department implemented new regulations for 2026 that anglers need to know:
Hook Requirements
- Miracle Mile and Afterbay: Single-point barbless hooks required. Any bait, lures, or flies permitted.
- Grey Reef and Cardwell: Single-point barbless hooks required. Artificial flies and lures only (no bait).
- Pegged attractors prohibited at Fremont Canyon and Grey Reef.
Why the Change
A 2023 Wyoming Game and Fish study found that 21.4% of trout in the Miracle Mile showed visible hooking injuries. The barbless requirement aims to reduce damage to catch-and-release fish.
Grey Reef Spawning Closure
Two reaches of Grey Reef are closed to fishing April 1 through May 15 to protect spawning rainbow trout: the short section between the gauge cable crossings roughly 700 yards below the dam, and the 1.2 miles from the Ledge Creek confluence down to S Gulch. Both are new for 2026 and both are signed. Full closure boundaries and the rest of the Grey Reef regulations.
Fly and Lure Zone Expansion
The artificial-flies-and-lures-only section at Grey Reef has been extended downstream to Government Bridge.
Commercial Guide Registration
Wyoming now requires all commercially guided fishing vessels to register annually ($325 fee), with visible registration documentation while operating.
Creel Limits
Miracle Mile: 3 trout daily, no more than 1 over 16 inches. Grey Reef area: check current Wyoming eRegulations for specific limits by section.
Gear Recommendations
Rods:
- 5-weight: Your primary nymphing and dry fly rod for both sections
- 7-weight: Essential for wind management (you'll use it more than you think), streamer work, and stonefly fishing on the Mile
Leaders and Tippet:
- 9-12 foot leaders tapered to 3X-4X for nymphing
- 5X-6X fluorocarbon tippet for clear-water midge fishing on the Grey Reef
- 0X-2X for streamers and stonefly dry flies
Other Essentials:
- Wind-blocking outer layer (seriously, the wind is relentless)
- Felt-soled or studded wading boots
- Wading staff for Miracle Mile cobble
- Quality polarized sunglasses (high desert glare is intense)
- Sunscreen and lip balm with SPF
- Cell phone charger (no cell service at Miracle Mile; plan accordingly)
Local Fly Shops, Guides, and Lodging
Fly Shops
Platte River Fly Shop (Casper): Operating since 1994, the longest-running fly shop and Grey Reef outfitter in the area. Located at 7400 State Hwy 220. Open Mon-Fri 8am-5pm, Sat 8am-noon.
The Reef Fly Shop (North Platte Lodge): The first permitted outfitter on the Grey Reef (since 1998). Located right on the river with lodging on-site.
Ugly Bug Fly Shop (Casper): Run by Crazy Rainbow Fly Fishing Guide Service. Full-service shop with guides for both Grey Reef and Miracle Mile.
Guide Services
Grey Reef Anglers: Experienced guides on both the Grey Reef and Miracle Mile. Float trips on StealthCraft drift boats.
- Grey Reef half day: $550/boat (1-2 anglers)
- Grey Reef full day: $675/boat
- Miracle Mile full day: $700/boat
- Miracle Mile extended (Bridge to Pathfinder): $900/boat
- Contact: 307-267-2559
Four Seasons Anglers: Guides the upper North Platte, Miracle Mile, and Grey Reef. Detailed hatch charts and fishing reports on their website.
High Plains Fly Fishing: Operates primarily on the upper North Platte and Miracle Mile. Float and wade trips available. Contact: 307-399-9464
Trout On Inn: Lodging and guiding combined, located 100 feet from the Grey Reef at Lusby. Offers drift boat rentals and shuttle service. Contact: 307-462-1917
Lodging
- Trout On Inn: Right on the Grey Reef. Guided packages with lodging and meals.
- North Platte Lodge: On-river lodging at the Reef Fly Shop location.
- Grey Reef Anglers Lodge: Full lodge operation with guides and accommodations.
- Casper hotels: Full range of options 30-50 miles from the fishing.
Book guided trips and lodging well in advance for spring (March-May) and fall (October-November). These are the prime seasons, and the best guides fill up months ahead.
Clear water over rocky cobble, the kind of readable structure that makes wade fishing productive
Hazards and Safety
Wind: The single biggest hazard on both waters. Sustained 20+ mph winds are common, and gusts can reach 40-50 mph. This affects casting, wading stability, and hypothermia risk. Don't underestimate it.
Cold water: Tailwater temperatures stay in the 38-46°F range year-round. A wading slip in winter is a genuine emergency, especially at the Miracle Mile where help is far away.
Remote access (Miracle Mile): No cell service, no paved road, no nearby services. Carry emergency supplies, a first-aid kit, and let someone know your plan.
Spring spawning closure: Respect the new April 1 through May 15 closure on the upper Grey Reef. Fishing in closed areas puts the resource at risk and carries stiff penalties.
Private land: Stay in the water or at public access points. Wyoming trespass laws are enforced along the Grey Reef corridor.
Frequently Asked Questions
What is the Miracle Mile in Wyoming?
The Miracle Mile is a 5.5-mile stretch of the North Platte River between Seminoe and Pathfinder reservoirs in central Wyoming. It holds over 3,200 trout per mile, including rainbow and brown trout exceeding 20 inches. The name comes from the exceptional concentration of trophy fish in a short section of river, fed by cold, nutrient-rich reservoir releases.
Where to fish the Miracle Mile?
The best access is from Miracle Mile Road off Highway 220 between Casper and Rawlins. Key spots include the Miracle Mile Bridge access, the Pathfinder Reservoir inlet, and several pulloffs along the dirt road. Wade carefully -- the bottom is rocky and uneven. Flows between 400 and 1,200 CFS are ideal for wading; above that, consider a drift boat.
What is the best time of year to fish the Miracle Mile?
Spring (March through May) is prime for rainbow trout on egg patterns and midges. Fall (October through November) brings the brown trout spawn with trophy fish on streamers. Summer offers consistent dry fly fishing with PMDs and caddis. Winter fishing is productive but demands cold-weather preparation -- the remote location has no services.
What's on the menu
Everything this river feeds, by month. Filter by bug, category, or fly size, and switch the axis to see what comes off at what time of day. Pulled from our western hatch and forage guide.
Wyoming
North Platte
Everything
Everything
Across the year
Any size
JanFebMarAprMayJunJulAugSepOctNovDec
Salmonfly#4-8
North Platte (Grey Reef)How much is onEverything above, added up
Category
Terrestrial
Forage
Peak weeks
How dependable
Dependable
Weather dependent
Roll of the dice
Window vs shapeTwo different things are stacked on each row. The window is specific to these rivers, taken from fly shop and outfitter hatch charts, guide reports, and our own river guides. The shape of the curve is the insect's typical emergence profile from published sources, drawn across that window. It models a normal year, not this year. Dashed bars mean we have timing but no sourced emergence profile, so no curve is drawn.The three categoriesHatches are aquatic insect emergences. Terrestrials are land insects that end up in the water: hoppers, ants, beetles, spruce moths, cicadas. Forage is everything else on the menu, from mysis and sowbugs to crayfish, eggs, sculpins, and mice. Forage is available whether or not anything is emerging, so it sits outside the “how much is on” totals, which measure bug activity only.
Using RiverReports
Check current North Platte River flows on RiverReports before every trip. The tailwater character of both sections means flows can change based on dam operations, sometimes with limited notice.
What to watch for:
- Miracle Mile at 400-1,200 CFS: Your wading sweet spot. Higher than 1,200 and you'll want a drift boat.
- Miracle Mile above 2,500 CFS: Experienced oarsmen only. This water has historically run over 10,000 CFS.
- Falling trends in fall: The signal that the river is transitioning to winter base flow and brown trout are on the move.
- Historical data: Compare current conditions to the 10-year average to gauge whether conditions are normal, high, or low for the date.
For Grey Reef flows, the release calendar, and what each level means, see the Grey Reef guide.
The flow data updates continuously, so you can make real-time decisions about which section to fish and whether to wade or float.
River Intel Weekly
Weekly flow updates and fishing intel.
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