It doesn't matter what part of the country you live in, there is more than likely a river nearby that offers quality mayfly hatches in June, July and August. Whether you fish water on the East coast or Mid Western states like Montana, I can almost guarantee there to be a species of the Ephemerellidae family flying around. What species type is another question but here in the Midwest there are 4 prominent species commonly called blue-winged olives to name a few.
For Colorado, The Colorado River has a large abundance of hatches to admire. Mayflies, stoneflies, and caddis are all found in large numbers. Pale morning duns, BWO's and tricos make up most of the mayfly hatches and keep the summer fisherman coming back for more each Summer. The spring Blue-winged Olive hatch on Utah's Green River may be one of the best match-the-hatch dry-fly experiences in the world. The #16-20 mayflies hatch from late March to the first week of May.
What about the Yellowstone Area you ask? Large amounts of Mayflies can be found just about every month in the Yellowstone area. Most of the Mayflies are particularly in large volumes from May through October and are an important food source for trout during this time period. Mayflies are the reason many of the abundant fly fishing opportunities arise during the Summer and late season.
Top Western hatch chart listings are always helpful,I can attest with my fishing book which has about 60 for just about every popular river in the states I've collected. Orvis has nice Hatch Chart as well as the go to Trout site Troutnut.
Looking for books on Top Western Hatches? We also have quite a few listings to help assist you in your search for Mayfly's. I know I've enjoyed many of these books over the past in my library but still anemic when it comes to the newer books out there so I need to get on the ball. Let us know if you have other books out there that we have not listed.
A few of our popular Western Hatch books include:
Dave Hughes "Complete Book of Western Hatches"
Jim Schollmeyer "Hatch Guide For Western Streams"
Dave Hughes & Rick Hafele "Western Mayfly Hatches: From The Rockies To The Pacific"
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