Baetis Time In The Rockies

Baetis Time In The Rockies
Beautiful Brownie

The Baetis, or Blue Winged Olive (BWO) is a Mayfly commonly found hatching on most western waters both spring and fall.  On rivers that close for the winter the BWO hatch is often the anglers last chance at rising fish before the seasons end.  On the flip side, BWO's are often the first Mayfly hatch of spring which frequently helps fly fishers emerge from the depths of the past winter.

Baetis tend to be small, #16's are considered huge, and most hatches are #18's and smaller.  On a recent float down a western water I encountered a prolific Baetis hatch and caught a little video of the micro-Mayflies as they drifted down the river.  View it here:

Baetis, like most Mayflies, swim to the surface, break free of their nymphal shell and emerge on the rivers' surface into an adult.  At this point they drift on the surface while their wings dry.  Once dry, they fly away, temporarily escaping feeding Trout.  The warmer the weather, the less time they spend on the surface and the less likely the Trout are to take advantage of the vulnerable Mayflies.  In cooler weather (especially overcast or rainy days) the tiny Mayflies spend extra time on the surface waiting for their wings to dry before they can fly away.  This causes large numbers of Mayflies to be drifting on the surface for extended periods which in turn offers Trout an all you can eat lunch.  These are the days many anglers stay home because it isn't bluebird weather.  Don't make that mistake, watch for the cloudy days, toss your Gore-Tex jacket in the gear bag and hit the water.

Fall is a great time of year, enjoy the changing leaves and Trout packing on weight to survive the winter ahead.  It won't be long before old man winter is here!

Recommended for You

United States

Saving the Chattahoochee River

Ross Purnell - April 23, 2019

How an Atlanta craft brewery is helping to save Georgia's most important trout stream.


Fly Fishing Community Stunned by Twin Slayings on Belize Saltwater Flat

Fly Fisherman Online Staff - June 27, 2019

The fly fishing communities in the U.S. and Belize are mourning after twin slayings that...


2019 Most Endangered Rivers

Fly Fisherman - April 16, 2019

American Rivers today released its annual list of America's Most Endangered Rivers,...

See More Recommendations

Popular Videos

Amazing Zipless Fly Vest!

William Joeseph introduced a remarkable zipper-free fly pack that features a surprising watertight magnetic seal.

Casting Backhand in Tight Quarters

A backhand cast is when you use your backcast to deliver the fly.

Basic Fly Casting

When learning to fly fish, casting is the first thing to master. Lean what to do, and not do, to successfully make a short fly cast.

See more Popular Videos

Trending Stories


5 Best Trout Fishing Spots in the World

Ross Purnell, Editor

Fly-Fisherman Editor Ross Purnell shares his top five best trout fishing destinations in the...


Picking the Perfect Fly-Fishing Leader

George Daniel - January 22, 2018

George Daniels offers his advice on which types of fly-fishing leaders are best for the most...


Alpine Lakes for Remote Monsters

Landon Mayer - April 18, 2018

You don't always catch large trout in these alpine lakes and streams, but even the small ones...

See More Stories

More Learn


Smooth Operators of The Complete Cast

Lefty Kreh & Ed Jaworowski - March 20, 2018

Based on Chapter 9 of The Complete Cast, Ed Jaworowski and Bernard 'Lefty' Kreh give some...

Fly Tying

Tying the Strong Arm Merkin

David W. Skok - July 09, 2019

Here are step-by-step instructions for tying the Strong Arm Merkin fly.

Fly Tying

Tying Grillos's User Friendly

Charlie Craven - December 19, 2018

Trout can't resist it, and it's easy to keep it floating.

See More Learn

GET THE MAGAZINE Subscribe & Save

Temporary Price Reduction.


Give a Gift   |   Subscriber Services


GET THE NEWSLETTER Join the List and Never Miss a Thing.