Wyoming
North Platte River
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About North Platte River
Central Wyoming's North Platte is a string of dam-controlled tailwaters that produces some of the highest trout densities in the West. The named fly fishing water is concentrated in three sections — Miracle Mile, Fremont Canyon, and Grey Reef — together totaling about 100 miles of cold, fertile, year-round river. Grey Reef in particular is rated Blue Ribbon by Wyoming Game & Fish and supports more than 8,000 trout per mile in its upper twelve miles, averaging 16-19 inches.
It fishes as a tailwater first. Flow is regulated by Kortes, Pathfinder, and Alcova / Gray Reef dams; releases are tuned by the Bureau of Reclamation for irrigation rather than fishing, so seasonal flow patterns matter a lot. Sow bugs, scuds, and small midges drive the bug calendar — these aren't classic salmonfly-and-PMD freestoners. Mid-summer Trico spinner falls and fall BWO hatches open dry-fly windows, but the daily bread-and-butter is deep nymphing heavy attractor rigs through long runs. Streamer fishing is excellent fall through spring, especially for the resident brown trout in the deeper holding water below Grey Reef and through Miracle Mile.
The corridor town is Casper, an hour east of Grey Reef and 90 minutes from Miracle Mile and Fremont Canyon. Driving distances put the river outside most weekend trip ranges, which keeps pressure manageable even on the famous water — locals and destination anglers split the traffic. The 2026 regulation refresh tightened gear restrictions: single-point barbless hooks are now required on Miracle Mile, Alcova Afterbay, Fremont Canyon, and Grey Reef; pegged attractors are banned at Fremont Canyon and Grey Reef; the artificial-flies-and-lures section at Grey Reef extends downstream to Government Bridge; and a new spawning closure from Ledge Creek downstream is in effect April 1 – May 15 each year. Note that current Grey Reef flow data comes from NWPS observation only — the USGS Alcova gauge no longer reports live data.
Species
- Rainbow Trout
- Brown Trout
- Cutthroat Trout
- Mountain Whitefish
| Species | Abundance | Best Season | Size |
|---|---|---|---|
| Rainbow Trout | Abundant | Year-round | 14-22" |
| Brown Trout | Common | Sep-Nov | 14-26" |
| Cutthroat Trout | Rare | Year-round | 12-16" |
| Mountain Whitefish | Common | Year-round | 10-16" |