It's blue-winged olive time! Make sure you have plenty of Baetis nymphs! Some of my favorites include: Sparkle Wing RS 2's, Mercury Flashback Pheasant Tails, Mighty Mite Baetis, Juju Baetis, Stalcup's Baetis, Mercury Baetis, Smitty's Baetis, and Foam Wing Emergers! Trout are starting to key heavily on Baetis nymphs in the shallow riffles!
March and April can be two of the best months to fly fish in the central Rockies. The big spring midge has been "coming off" and I saw my first blue-winged olive on the South Platte River a few days ago. These are all signs that spring is almost here!
With increased feeding opportunities, the fish are now moving back into the riffles and feeding hard. Make sure you have plenty of midge pupa in sizes 18-24 and lots of Baetis nymphs in sizes 18-20. Dry fly enthusiasts are finding their fair share of rising fish in the slower pools and tailouts too.
It's hard to go wrong with a size #20-22 Matt's Midge or a size 24-26 Parachute Adams to fool the midge feeders that are focusing their attention on the adults. A size 20 Mathew's Comparadun has been effective in fooling trout keying on mayfly duns.
Tom Redmond fooled this beautiful 20.5 inch South Platte rainbow a few days ago on a size 20 Mercury Midge during the afternoon midge-bite. The big spring midge (size 18) is now hatching and trout are responding to them nicely.
Pat Dorsey is an author and fly fishing guide. He is a co-owner of the Blue Quill Angler in Evergreen, Colorado.