Fly Fishing on the "Upper" Colorado River

Fishing Access on the "Upper" Colorado River

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Although the Colorado River traverses nearly 250 miles from its headwaters in Rocky Mountain National Park to the Colorado/Utah state line, I'll only be discussing the 50 (or so) miles from just above Hot Sulpher Springs to near its confluence with the Eagle River at Dotsero. Although there is some nice small-stream fishing up near the headwaters, there's a lot more closer to home (for me). Below the Eagle, the river is generally just too big (and dirty) to bother with. Below Glenwood Springs (& the Roaring Fork River), you're down to Whitefish, Carp, Suckers, a few Small Mouth, and very few Trout. For the sake of simplicity, I've divided the "prime" portion of the Colorado into two sections hereafter referred to as the "upper" and "lower" Colorado.

The "upper" section begins just below Windy Gap Reservoir (15 mi. East of Hot Sulpher Springs) and extends down-stream to the "Pumphouse" river access (below Kremmling). This part of the river is essentially a very big, freestone "meadow" stream with shallow riffles and fast runs interspersed with long, slow glides and slicks. Just to keep things interesting, there are the 4-mile-long Byers and Gore Canyons at either end which provide some really "heavy-duty" pocket water. I've also included short stretches of the Blue and Williams Fork Rivers above their confluences with the Colorado.

"C-40" Ranch

Immediately upstream from the town of Hot Sulpher Springs, the Colorado flows between the Thompson and Douchette Ranches which have leased fishing rights to the Rocky Mountain Angling Club. Until the long-term effects of Whirling Disease became apparent a couple of years ago, this was one of the finest pieces of trout water I'd ever had the pleasure to fish & guide on. Although about 1/3 of the water is basically "unreadable": 80' wide, knee-deep bank-to-bank, fairly slow flowing with a slightly "ruffled" surface, and absolutely no conspicuous rocks, channels, or weed-beds that say "Cast here!"; there were big, colorful Colorado River Cut-Bows scattered all over the river -right out in the open! Fortunately, as the surviving 'Bows die of old age, most of their "niches" (except these "flats") will be taken over by W.D.-resistant Browns. There are still quite a few old 'Bows around - it just takes a lot more careful stalking to find them.

Byers Canyon

Just below the town of Hot Sulpher Springs (there really is one - with a spa & pool), the Colorado River drops into Byers Canyon -- 4 miles of deep, strong-flowing "pocket water". Although access is good - in the sense that there are several pull-offs on the highway, the bad news is that you still have to scramble down several hundred feet of boulders to get to the water. For the dry-fly folks, you'll have to look for spotty, but heavy, Baetis hatches in the Spring & Fall, or "pound-up" small fish along the edges with the ever-present Caddis. If you don't mind "slinging lead", bring a 6 or 7 wt. and fish big (up to #4) stonefly nymphs as deep as you can get 'em or try working a big Zonker or Wooly Bugger through the pockets.

"Hot Sulpher Springs" S.W.A.

The river slows and widens quickly after leaving Byers Canyon. Below U.S. 40, the river runs through the D.O.W.'s "Gilbert" and "Lone Buck" units where there are several large islands which create sub-channels offering a great variety of fishing opportunities and making this 3-mile stretch wadeable most of the year. The Gilbert Unit features a large picnic area with tables & fire-pits among the Cottonwoods, and there are a few nice (unimproved) camp sites just down-stream at the Lone Buck Unit.
The riffles and fast runs here can be productive year-round using dark Stonefly, Bead-head Prince, Pheasant Tail, & Chamois nymphs. If you actually enjoy fishing San Juan Worms (or want to train the fish not to eat the W.D.-carrying naturals), try them in the plunge-pools below the irrigation weirs at "Lone Buck" and the pocket-water up at "Gilbert". For breaking the Winter-long dry fly drought, fish can often be found rising for Midges, tiny "Snowflies", and Baetis starting early in March. The Salmon Fly hatch in early June can be impressive, but the fish only seem to pay attention to them about 1 out of 5 years. After the river starts to clear and drop in July, & clear on into early October, a "Hopper / Dropper" rig can be effective during non-hatch periods when you'd rather not nymph deep. Be prepared for brief caddis hatches early in the afternoon and ovipositing flights in the evening. A variety of small pale Mayflies all commonly referred to as "Pale Morning Duns" appear throughout the summer (most often mid-day and 3-5 p.m.) which can be tough to match, so try to have a couple of different "Cahill" or "P.M.D." type patterns.

"C-41" Ranch

Immediately downstream from the "Lone Buck" S.W.A., the Rocky Mountain Angling Club has leased about 1-1/2 miles of the prettiest trout-water you've ever seen. The river here averages about 80' in width as it flows through hay meadows lined by huge cottonwoods which shade one side of the river or the other almost all day long. The middle section of this lease is characterized by broad, shallow "bays" formed by a series of gravel bars along the North side sloping gently out to a deep main channel. The upper & lower ends of the property have excellent pocket-water with large widely-spaced boulders.
The water is easy to "read" and like many rivers, it can be almost ridiculously easy to move fish on a good day, but when the fish are not suicidal, it's nowhere near as easy to fish effectively as it looks. When the fish are rising, long leaders and excellent line-control are necessary to overcome the many invisible micro-currents and there are a couple of long, glassy-smooth glides where fooling big fish sipping Midges or B.W.O.s can be as technically challenging as on any Spring Creek. If you're dredging the bottom with nymphs, expect to be fine-tuning your weight constantly as water depth & speed change -- again, line-control and drag-free drifts are essential.

Williams Fork Reservoir

Here's Mountain Angler guide Pat ("Anything that Swims") Chant with an "average" Pike taken on a fly wade-fishing at Williams Fork last June. While we don't generally do a whole lot of still-water fishing, the "stockers" around the inlet sometimes provide a "bail-out" when the wild fish in the rivers haven't been cooperative, and the Pike are generally "On the Bite" in early June when many of our rivers are only marginally fishable. Since casting and stripping big streamers can be tiring after a couple of hours, this is usually a "diversion" at the end of a day on the river below the dam.

Williams Fork Tailwater

The 3 miles of the Williams Fork River between Williams Fork Reservoir and its confluence with the Colorado at the "town" of Parshall provides some of the best fast-water nymphing around. Although this is one of the primary spawning tributaries for the Colorado River Cut-Bows, Whirling Disease has apparently not become a problem (yet), so you can find both wild Browns and 'Bows here. The stream is only about 30' wide and follows a fairly steep gradient all the way down, so you'll find primarily fast runs and pocket-water with just enough riffles and pools that you shouldn't have too much trouble finding good "dry-fly" water during a hatch.
Although there is a solid 20-minute hike in to the river, the quality of the fish pretty much guarantees that you'll be fishing 2nd- and 3rd- hand water most of the day, so take your time and fish everything very thoroughly -- including the hard-to-reach or less-than-great-looking areas that others have probably ignored. Many people seem to leave the river by mid-afternoon, so be prepared to stay and fish late (most of the best hatches come after 3 p.m.). Also, since the general migration of fishermen is up-stream, consider taking a short break and moving back down toward the lower end late in the day.

"Breeze" S.W.A.

The "Breeze" State Wildlife Area encompasses about three miles of the Colorado River downstream from its confluence with the Williams Fork near the town of Parshall. It is characterized by wide riffles & long, slow runs with very few rapids or heavy pocket-water. The aquatic insect life here includes at least a dozen species of Mayflies, eight Caddises and a half-dozen Stoneflies. On late summer afternoons you may find multiple hatches with fish feeding selectively on one particular insect (usually the least obvious one) or (worse yet) different fish each looking for a different bug or stage of emergence than his neighbors!
Nymph selection is pretty straight-forward with big Stones (dark brown or golden), mid-sized Bead Princes & Hare's Ears, and tiny Pheasant Tails leading the list. When the fish are "Up", though, it's a different matter altogether and you probably won't be safe leaving any of your fly boxes behind. Beware of believing that our "Pale Morning Dun" and "Blue-Winged Olive" hatches actually refer to specific mayfly species. In actual fact, there are 3 distinctly different Baetis & Psuedocloeon species called "Bee-Woes" and species from 6 genera in 3 different Families are sometimes called "P.M.D.s"; so any #14 - #16 "Cahill" / "Pale ... Dun" or #18 - #24 "Blue-Winged Olive" / "Baetis" Adult or Emerger variation you come across deserves a chance!

Blue / Colorado Confluence

Immediately downstream from the "Trough Road" the Blue River flows through B.L.M. lands down to its confluence with the Colorado. I've included this piece of the Blue in the "Colorado" section because it looks and fishes much more like this part of the Colorado than any of the rest of the Blue and because there is virtually no other public access on the Blue for many miles upstream. Before entering, you must get permission from the land-owner just across the bridge.
The river is wider and slower here, so the wading involves soft bottoms and weak banks rather than fast water or slick rocks. The quality of the fishing can vary widely - from a total waste of time to dozens of fish rising for hours at a time due to fluctuating releases from Green Mountain Reservoir. The one thing you can count on is few, if any, other fishermen since this section of river is unmarked and only accessible from one spot!

Gore Canyon

Just below Kremmling, the Colorado enters Gore Canyon - four miles of steep, fast rapids, riffles, & pocket-water down to the "Pumphouse" State Recreation Area. To access this part of the river one can either fish up-stream from Pumphouse or follow the railroad down from the top of the canyon and fish back up. This latter option will get you to some great water that sees very few fishermen, but "walking the tracks" is not easy - especially when you have to get through several tunnels not knowing when the next train may come through!
This short canyon seems to be a barrier preventing the Whitefish common in the "lower" river from moving farther up, and also (so far) stopping the down-stream spread of Whirling Disease. Whatever the reason, just rolling a few rocks shows a dramatic increase in number & variety of aquatic insects which means you could find almost any of our important Stonefly, Mayfly, or Caddis hatches here. In actual practice, however, you'll seldom find fish feeding on the surface even during good hatches, so be sure your nymph boxes are well stocked.