North Platte – Grey Reef

Admittedly, I've only visited the Grey Reef one time in September of 2025.  It was multiple warm, mostly sunny days.  We came for the morning midge hatch; very prominent at the put-in ramp.  We stayed for the fish that live in this tailwater.  Below Grey Reef Dam near Alcova, southwest of Casper, the North Platte runs cold, rich and loaded with rainbows that look like they spend their off-hours lifting weights.  There are some chunkers.  But it's not easy fishing.  It is flat water for the most part.  You may spend a lot of time rowing over very deep pools, but the fish don't seem to be where you think.  So yeah, it's challenging.  And watch out - not if, but when, the Wyoming wind blows. 

Numbers and Size

The Grey Reef is known for some of the highest trout densities in the West, and plenty of those fish are thick, hard-pulling rainbows. It's float-fishing heaven, and it's open year-round.  Plus there's some really fun accommodations to stay in close to the river.  You can really maximize your fishing here.

The fishing

Drift boats and nymph rigs under an indicator: worms, leeches, scuds and midges. It isn't glamorous, but it's deadly. Streamers along the banks shine when the water has some color. Dry-fly days do happen, but this is mostly a subsurface show.

When to go

Year-round. Spring is famous, especially when the dam runs a flushing flow that stirs up the riverbed and sends the fish into a feeding frenzy. Summer and fall are steady, and mild winter days can mean quiet floats and very happy anglers.  But watch out for weather.  It can change quickly and you could be miles from the finish.

Guide's note

About that wind: bring a heavier rod, work on a tight casting loop, and don't be shocked when your indicator goes airborne. You'll need a Wyoming fishing license, plus a good net, because the fish here are not small.