Your “Must Have” Flies for Fishing Colorado Streams

by John Haile, ETU Secretary; photos by Tim Stechert

You voted on what should be the dozen flies any serious angler should have in his fly box if start­ing out to fish Colorado’s world-famous trout streams…

…and what you came up with was not just a dozen, but a “baker’s dozen” flies that Pat Dorsey, the man known as perhaps the top guide in the state, says you could take anywhere in the West and catch fish. “They make a fine fly box,” he says.

ETU members had little doubt about the top two-thirds of the list. They were close to one mind about these, especially since we didn’t specify size or color:


#1 Top Fly

copper john

#2 Top Fly

  1. Parachute Adams
  2. Copper John
  3. Elk Hair Caddis
  4. Pheasant Tail
  5. Woolly Bugger
  6. Blue Wing Olive
  7. RS II
  8. Stimulator

  9. After the first eight, the votes became much more split. Some folks voted for more midges; others believed there need­ed to a hopper or a stonefly, or perhaps something else that could serve double duty. The choice, though, was this:
  10. Mercury Midge
  11. Black Beauty
  12. Ant
  13. San Juan Worm
  14. Prince Nymph

So, why 13 flies? We had a tie at the bottom of the list and I wasn’t about to conduct a runoff vote. Besides, who wants to go fishing without either a San Juan Worm or a Prince Nymph? The worm is good in any stream, especially as a dropper. And the Prince Nymph can fill several roles, depending on size and how it is fished. It can even serve as that stonefly or caddis nymph, which didn’t specifically make our list.

What else is missing? When I asked around the Blue Quill at a fly tying session there a few weeks ago, the first response I got from almost everyone was “an egg.” The guys also had some ideas about why one wasn’t on the list.

Roger Bittell, a long-time guide who helped popularize the egg in Colorado, said he still finds that a lot of fly fishermen “just don’t consider it a fly.” “ Sometimes people are a little afraid to fish the egg,” he said, “but fish are spawning in the streams out here pretty much year round now, and it’s going to catch fish.”

There was also some concern that our list was tilted too much toward tailwaters, because of the number of midges chosen. The lake fishermen would have made a couple of substitutions, too. But, we did specify that this was for “Colorado streams.”

Overall, people in the know really liked the selections. After all, we limited ourselves to a “baker’s dozen” and we acknowledged that this was what an an­gler could start with. We figured people would choose a range of sizes and colors for each.

wooly bugger

As we went through the nomination and voting process, several of our members expressed preferences for certain variet­ies of these flies. For example, the black or the olive Woolly Bugger, which imi­tates either a minnow or a leech, seems to be a preference. The red Copper John, a great multipurpose nymph, ranks high on most lists. Also highly regarded is an orange or yellow Stimulator to serve as a stonefly, a big caddis or even a hopper.

rs II

In recent years, Bob Churchill’s sparkle wing RS II has become a favorite of many of our members. The RS II pictured here is closer to the original as tied by Rim Chung, except that he used the web of a saddle hackle feather for the wing rather than antron, z-lon or sparkle wing. (Bob’s pattern is on the ETU web site.) You can fish the RS II to simulate pretty much any emerging mayfly nymph, but mainly a Baetis. It also works great as a midge pupa during the winter months.

amys ant As for an ant, currently the Amy’s Ant is hot as a multi-purpose foam ant, but the traditional, smaller foam, dubbed or thread ant continues to be especially effective, even if not as versatile.


Even the Elk Hair Caddis, which serves as our adult Caddisfly, is being fished in various forms. A number of ETU members like the wrapped-foam version developed by Larry Kingrey down in Canon City. (Tying instructions avail­able on the ETU web site.) There’s also a simpler, flat-foam body version popular on the Arkansas River around Salida. Then there’s always the traditional pat­tern shown here.

Dorsey says the main thing with choosing a fly is to pick something you believe will catch fish. He calls it your “confidence fly.” Don’t know why, but you will just catch more fish on that one fly, he says.

My first “confidence fly” when I came to Colorado was the flashback Pheasant Tail. More recently, it has been the Black Beauty.

Suggests one of the other guides listen­ing in on our conversation: “Maybe it’s just because you fish it all the time. Why wouldn’t you catch more fish on it if you’re not fishing any other fly?”

So much for the wisdom of choosing flies for catching fish.

As for the other flies on our list…

The Parachute Adams is a good all-around adult mayfly pattern.
It is so good, in fact, that it was the No. 1 choice in our poll.
Even if the fish are mostly feeding below surface, fly fishermen just won’t give up trying to bring the trout to the top.

pheasant tail

Our Pheasant Tail serves as another Baetis nymph or as pretty much any mayfly nymph. The pattern shown here is a standard PT, though the flashback pattern is definitely popular, especially in the riffles, along with a bead head pattern to get the fly down in the water column more quickly.


The Blue Wing Olive is a classic adult Baetis or other mayfly pattern. It is simple yet elegant. Few flies are as pretty with a soft cast to a rising fish. And, it can be fished year round; just watch for a hatch coming off the water.

mercury midge

The Mercury Midge has Colorado writ­ten all over it. Pat Dorsey created it for the South Platte River and has watched it evolve into a fly used all over the West. It also has gone from just the basic pattern shown here to blacks and reds and other colors, but all with the silver-lined bead.
The Mercury Midge imitates a midge pupa just before emerging as an adult and normally is fished just below the surface. When there’s no hatch going on, Pat will dredge it deeper as an attractor.

black beauty

The next fly on our list is another Dorsey creation: the Black Beauty. It is an ear­lier stage pupa imitation and is normally fished deeper. Any time I’ve seen the stomach of a fish around here “pumped,” it was filled with small bugs that looked like Black Beauties.
In the cold tailwaters we find in many areas of Colorado, small midges are the main food source for the trout, so flies such as the Mercury Midge and Black Beauty are fished small, as in sizes 18 to 22.

san juan worm

The worm is just a worm, and it works. Pick your color. Do the fish care? For whatever reason, red and pink, especially hot pink, seem to work best. Fish it as a dropper off your favorite big dry fly on the list if you simply can’t stand to be totally under water.

The main thing, though, is that ETU mem­bers picked these flies because, more than anything else, they consistently catch fish. They are a great start to any fly box. And, it’s no wonder Dorsey liked the list. When I asked him what he thought of it, I didn’t realize two of his own creations had been picked. He should have loved it.