The Great Hatch
Part of an article published a couple of years ago in Fly Fisherman Magazine by Bill Edrington , Owner of Royal Gorge Anglers in Canon City, Colorado.

It's very timely since this hatch will be starting very soon. The 4/5/05 report from Bill Edrington reads as follows:

"……the water around Canon City to Parkdale is reaching the mid 50s and cased Caddis are closed. This indicates that these bugs should start to hatch by this weekend if not sooner. I would expect to see Caddis at least up to Five Points by Saturday."
The mother of all Mother's Day Caddis hatches occurs on the Arkansas. The caddis (Brachycentrus) hatch when the water temperature reaches about 50 degrees F. The hatch begins in the Canon City area around April 15 and gradually moves upstream past Salida until runoff blows it away, usually around May 15. The irony is that by Mother's Day the fish have seen so many bugs that fooling them with an Elk-hair Caddis is impossible.

When people call me and want to know where the hatch is, I simply tell them to drive until they can't see out the windshield. Then stop, clean the glass, and drive three or four more miles upstream. The goal is to get above the blanket hatch so that fishing a dry fly can be more productive. Having bugs on the water is good, but during this hatch there can be too many. Picking out your fly on the water can be impossible, let alone picking the naturals out of your ears and nose. My friend Rod Patch in Salida calls this a "breathe-through-your-teeth kind of hatch."

You need to think your way through this hatch. As it begins, the larvae patterns are important. I usually drift them behind big stonefly nymphs, such as Larry Kingrey's Arkansas Rubber-leg Stone. Next comes a pupa fished as an emerger by swinging it downstream. Then comes the adult, and then the spent caddis.

During the waning days of the hatch, the spent patterns always take big fish late in the day. My favorite spent pattern is Mike Lawson's Spent Partridge Caddis in a #16. The best adult pattern is a #14 Elk-hair Caddis with a peacock body. Almost any larva works well. Kaufmann's Bead-head Metallic is a good choice, as well as the old latex standbys.
The most important pattern is the pupa. You can't go wrong with LaFontaine's Sparkle Emerger or Kingrey's Bubble Pupa. All of these flies are necessary to be successful through the entire hatch. There are days, however, when just fishing an Elk-hair Caddis can bring 75 fish to hand. These days occur around the third week of April, before the fish are "bugged" out. Other Hatches If you have a new dry-fly rod to break in, take it to the Arkansas and book a room for the entire month of April. The first hatch of spring is a Blue-winged Olive (Baetis), and the hatch can be spectacular on cloudy days in late March and early April. Light snowfall can generate hordes of the bugs and start a daily feeding frenzy.
The best time to fish the Arkansas is mid-April. It gives you intense Olive hatches, great caddis larva and stonefly nymphing, and the beginning of various caddis hatches along the lower corridor.