Fly Fishing the Upper Rio Grande: Colorado's Best-Kept Secret

Standing beside the crumbling adobe barn across the river, the old mule eyed me with contempt. I was wading mid-current in heavy water, working hard to get on top of my drift, and it looked like the animal didn't appreciate my presence.

"If she decides to come this way, I suggest you back out and go for the trees," said my guide. Joel had lived on the ranch for years and had experience in these sorts of situations.

Out of the corner of my eye, I watched my fly disappear in the middle of the big hole, and I missed, distracted. The mule slowly turned away, and I caught the scent of roasting chiles and mesquite. 

Silver Town

Stashed away in the mountains of southern Colorado near the old silver boomtown of Creede runs one of the best-kept secrets in American fly fishing, the upper Rio Grande.

Iconic in its association with the desert Southwest, the second-longest river in the U.S. is a muscular, high-volume flow running from its headwaters in the San Juan and Weminuche ranges, where snowpack often exceeds 400 inches per winter. Fat trout navigate big water here to chase some of the largest aquatic insects in the country, offering outrageous dry-fly fishing with patterns in sizes unheard of on tailwater streams.

The history of the Rio Grande runs deep as well, with thousands of years of settlements on its banks and struggles for the water it provides. From its source on the Continental Divide 30 miles west of Creede, the Upper Rio Grande winds down through steep canyons and high-altitude ranchland, passing the town of South Fork at its confluence with a major tributary. From there, the river heads east and flows into endless riffles before hitting the floor of the San Luis Valley at Del Norte, once a proposed territorial capital, now a rock climbing and mountain biking mecca. 

In 2001, the river was improved through a change in fishing regulations, allowing flies and lures only, and outlawing the use of bait. This has resulted in a steadily growing population of larger fish, with miles of recently designated Gold Medal Trout water.

The Rio Grande runs through some of the best agricultural country Colorado and New Mexico have to offer, and ultimately ends up dumping into the Gulf of Mexico where Texas and Mexico are left to fight over the scraps. Like her sister river the Colorado, the lower Rio Grande is heavily oversubscribed, and has a political history that is a subject in its own right. But the upper Rio Grande is a different story that shines with its own unique biology and tactics for fly fishers.

Heavy Hitters

Pteronarcys stoneflies are the Holy Grail for many Western anglers, and more than a few interstate road trips have been launched by an overnight phone call saying that the hatch is on. Salmonflies are among the largest flying insects in the world, requiring #6 to #8 hooks and heavy use of foam and hair to create patterns half the size of a badminton birdie. This handsome insect sports a brightly colored salmon orange neckband and slate gray wings, with the most effective fly patterns including a bright orange collar or other spot of color for fish to visually identify.

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Notorious for their short-lived emergences, Pteronarcys californica (Salmonflies) hatch for only a few days, and often during periods of peak runoff flow in the spring. Their hatches can be outrageously heavy, smearing windshields and clogging air intakes on approach vehicles, while feeding fish are going berserk in the rivers, gorging themselves on the flying equivalent of a porterhouse steak.

A big river in the throes of a full-on stonefly emergence is a heart-stopping sight for any fly fisher. Fish lose all fear and slash mercilessly at the struggling insects fluttering on surface, with the largest fish in the river getting in on the action and taking over the best runs. Watching a 20-inch fish launch out of the water to nail an insect the size of your thumb in midair burns into your memory, and for some, drives a lifelong fever.

Whatever ecology makes the Rio such a prime habitat for stoneflies seems to also drive a tendency for other insects to be on the big end of the scale. Following hot on the heels of the Pteronarcys hatch, large Western Green Drakes (Drunella grandis) make their appearance, often emerging within a masking hatch of remnant stoneflies. Some fish can become selective toward these mayflies while fly fishers miss the boat by focusing on the more obvious Pteronarcys.

A typical late June to July rig for a dry-fly angler in the area would be a #6 Stimulator with a #10 Parachute Adams or Green Drake imitation as a dropper and the takes tend not to be subtle. As local guides are fond of saying, "Go big, or go home!"

Dry-fly hatch season on the Rio is mid- to late summer, basically from the high water point of runoff through August, though on a river with such varied biology, other tactics can be used with great results. Early-season fish slam big streamers even at midday if the water is slightly off color, and the majority population of brown trout become absolutely ferocious during the late October spawning season, defending redds from egg-stealing dace and other minnows.

Nymphing during lower water in the late summer and fall allows fly fishers to wade close to uncommonly large structure, throwing large Prince Nymphs and Copper Johns to imitate stonefly nymphs, with Pheasant Tail or caddis emerger droppers typically bringing up the rear.

Historic Landscape

Fly fishing on the Rio has a long history. This is home water to a community of high-altitude hardcore sportsmen, multi-generational ranching families, and some locals with Spanish lineage dating back to the 1500s or the native Utes before that. Coronado's expedition to the Americas ended in the San Luis Valley of southern Colorado, with some explorers calling it quits on returning to Spain and founding the town of San Luis, which survives to this day.

The geology of the region is unusual. Like Yellowstone another region regarded for its excellent fishing the area is predominantly volcanic, and the largest known explosive eruption in geologic history was produced by the La Garita Caldera in the mountains east of Creede. A super-volcano 27 million years ago ejected enough ash and debris to cover an area the size of Southern California to a depth of 40 feet. This produced a volcanic plateau known as the San Juan Mountains that covers a vast area of southwest Colorado.

More recent volcanic activity in New Mexico blocked the Rio Grande's flow out of the San Luis Valley and created a large Pleistocene lake at over 7,000 feet in elevation. The lake had no outflow but was stable due to influx, evaporation, and seepage into the aquifer for 3 million years. Finally, sedimentation and high levels of precipitation allowed the lake to breach a low rise to the south, draining some 100 cubic kilometers of water and cutting the 600-foot-deep Rio Grande gorge west of Taos, New Mexico.

As a trout fishing resource, the Rio Grande is essentially a bifurcated river system. From agricultural impoundments high on the Continental Divide down into the western San Luis Valley, the river provides over 60 miles of coldwater trout habitat before it is subject to temperature and siltation changes due to low gradients and dewatering from agricultural canal systems.

In the central valley, northern pike and other rough fish dominate the river. Pike up to 50 inches long have been caught in the wildlife refuge near Monte Vista. Exiting the valley south of Alamosa, the river is significantly reduced in flow until it experiences recharge from the superb fisheries of the Conejos and Red rivers, cooling the water to become excellent trout habitat again in northern New Mexico. But it is the headwaters of the Rio Grande in Colorado that arguably provides the best opportunities and variety for fly fishing.

Local guide Kevin Leggitt owns and operates the Rio Grande Angler in Creede. Born and raised in the area, Leggitt bought the shop in 2000, and immediately began to think strategically about how best to address the resource to service his clientele. Contrary to most perceptions of the river as a thin, shallow stream, the Rio Grande is a large river in its first 60 miles, with steep banks and heavy runs. Wading in early to midseason can be a difficult proposition, and large sections of private ranchland west of Creede make walk-and-wade access difficult.

"We really started looking at the Rio as a float river in the early 2000s, by gearing up in a professional way with drift boats and framed rafts," said Leggitt. "With word getting out about the stoneflies and other large insect hatches that we have going on here during high water, it was obviously a best way to get after that."

Twenty miles downriver in South Fork, you'll find Leggitt's partner Joel Condren and his base of operations at 8200 Mountain Sports. Condren is also the founder and senior guide for South Fork Anglers and Mountain Man Rafting. "This river has the most amazing biology, and it changes mile to mile. One section can be heavily slanted toward stoneflies, and the next will have a huge population of Drakes or PMDs mixed with caddis. As a river guide, it keeps you on your toes," says Condren.

All this is not to say that the Rio is not a river for the privateer on foot. The Coller State Wildlife Area above South Fork offers an excellent resource for wading fly fishers who enjoy boulders and structure. In a great example of management in the public interest, numerous excellent access points near bridges with riverside parking areas have been leased by the Colorado Division of Parks and Wildlife, with different sections being suited to varying water levels and fishing styles. From Del Norte to South Fork, water tends to be big and open, for those who are into booming casts and longer drifts.

The reason the upper Rio Grande contains such an impressive overall flow is because it is fed by a huge basin in one of the highest mountain precipitation areas in the West. Wolf Creek ski area just to the south is known for huge dumps of powder from winter weather systems coming out of the Gulf of Mexico, and the tributaries that feed the main stem of the Rio Grande are generally peppered with trout.

The South Fork of the Rio Grande—a major tributary runs from Wolf Creek Pass north to the town of South Fork, offering excellent dry-fly fishing with generally easy access near several national forest campgrounds. Other streams that run into the river typically have access points higher up in the national forest. Several upscale guest ranches have also operated in the area for over 100 years, with stocked lakes, private creeks, and guide services on the main stem of the Rio Grande.

Native Cutthroat Trout in the Rio Grande

Trout in the main river are self-sustaining populations of nonnative brown and rainbow trout, with some of the rainbows showing hybridization from interbreeding with cutthroat. Brook trout are common in the high-altitude streams as well, and in some places are prolific. I once had the privilege of guiding a skilled dry-fly fisherman into a 130-brookie day high above Creede on a tiny stream where almost every cast produced a fat 10-inch fish on an Elk-hair Caddis.

Native pure-strain Rio Grande cutthroat are rightfully the most prized trout species in the region, but are now only found in the highest reaches of isolated freestone streams. Only the most motivated and adventuresome fly fishers will ever encounter them, as Rio Grande cutthroat currently occupy only 10 percent of their historical range.

Greenback cutthroat were recently designated as Colorado's state fish, but these southern Colorado cutthroat are equally rare and beautiful. The value of native fish is not lost on the fly fishers of Colorado, and Trout Unlimited has been working with the state Division of Wildlife to help restore Rio Grande populations and habitat. TU's Rio Grande Basin Project manager Kevin Terry has a degree in fisheries biology and now lives in South Fork, where he is working with local communities on conservation and access issues. Terry splits his time between restoration and protection projects for Rio Grande cutthroats, and working with water users to help optimize use through strategies like timing of reservoir releases, leases, and efficiency upgrades to irrigation infrastructure.

"The local towns here are tight knit, with a strong sense of values and history. When we came in with proposals to help conserve water for habitat and other ideas, community leaders were very open to collaboration. I think there is a real sense that this whole valley is going to benefit from improved and protected resources for tourism, while being able to work seamlessly with the historical farming and ranching economy," said Terry. "After all, a main reason people choose to live here is for the quality of life, and fishing can be a big part of that."

Across the valley from the main stem of the Rio Grande, the northern Sangre de Cristo mountain range rises above Great Sand Dunes National Park, running up from New Mexico with peaks to over 14,000 feet in elevation.  

Here on the western slopes of the Sangres, Sand and Medano creeks flow as perennial water sources. These streams historically flowed into the previously mentioned Pleistocene Lake Alamosa, which undoubtedly shared populations of trout that lived in the Rio Grande.

With the geologic events leading to the catastrophic draining of the lake, the populations of aboriginal fish in the Sangre de Cristo became geographically and genetically isolated. That the streams never dried up completely during historical droughts is nothing short of a miracle.

Medano Creek now has a tiny restored population of Rio Grande cutthroat which had been subject to overfishing, and there is a similar population in Sand Creek where a downstream sand dune barrier prevents upstream migration of nonnative species like rainbow trout. Remnant populations of pure-strain Rio Grande cutthroat have been documented in other waters in the Sangres, but information about those places is closely guarded. 

Unlimited Fishing Potential

The Upper Rio Grande valley has remained relatively untouched compared to other Colorado waters due to distance and travel logistics. Five hours of driving from the major hubs of either Denver or Albuquerque, the San Luis Valley is also ringed by high mountain passes, with the only low-gradient access being up the river valley itself from New Mexico.

Despite the apparent lack of traffic, the area is located roughly midway between two of America's newest national parks—Great Sand Dunes and Black Canyon of the Gunnison and offers almost unlimited potential for wilderness recreation. There are currently four designated Wilderness Areas in the Rio Grande National Forest: South San Juan, Weminuche, Sangre de Cristo, and La Garita.

Miles of backcountry streams with developed 4-wheel-drive roads crisscrossing the high country give access to excellent small-stream and high-lake fisheries in mid- to late summer. However, fall comes early at this elevation, and fly fishers mostly concentrate on the main stem of the Rio Grande itself from mid-September on.

The general consensus is that the Rio Grande is a biological anomaly in that it is by definition a large-volume tailwater that fishes like a freestone stream, with large insects and everything else that entails. The late season is especially aesthetic, with massive stands of aspens and cottonwoods turning to autumn colors over low, clear water.

If you're looking for a destination fishery far from the crowds, southern Colorado is hard to beat. For motivated fly fishers, the Upper Rio Grande and the surrounding region is an unspoiled playground to be explored.