INFORMATION ABOUT BUGS ON THE COLORADO
The Colorado River offers plenty of caddis hatches all season long. The Mother’s Day caddis hatch (Brachycentrus) is the first to come off and starts sometime in mid-April on the lower stretches near Rifle and Silt and steadily works its way upstream as water temperatures warm, normally reaching State Bridge around early May and middle park sometime after Mother’s Day. The bugs typically start hatching late in the morning during this time of the year and depending on the weather and water conditions, come off in waves throughout the entire day. This hatch can come off so thick the fish literally fill up on caddis adults and pupae. Fishing will be most productive if you hit the river just ahead (upstream) of the hatch or just behind it, but not right in the meat of the hatch. Expect excellent dry fly fishing until spring runoff brings an end to this incredible mating frenzy sometime in mid-to-late May. Several different species of caddis (including Brachycentrus) continue hatching, though not as heavily, throughout the summer months, especially at dusk.
The well-equipped fly fisherman should bring various caddis patterns imitating all stages of development to the Colorado River. Although trout will frequently rise to caddis imitations when used as a searching pattern, you will have more success if you match whatever stage of the insect’s life cycle the fish are keyed in to. Patterns such as the Breadcrust, Sparkle Prince, Peking Caddis, and LaFontaine’s Caddis Pupa are a few patterns that work well when imitating subsurface caddis activity. Popular dry flies include standard Elk Hair Caddis and Peacock Caddis, Ginger Variant, and Stimulator in appropriate sizes
If you are not having success during a caddis hatch with dries on the surface, switch to a below-the-surface pattern. For every adult caddis fly devoured during a hatch, a trout undoubtedly eats several pupae.
Purchase Fishing Map & Floater’s Guide to the Roaring Fork & Fryingpan for more detailed information.