The quality-water stretch of New Mexico’s San Juan River offers exceptional fly fishing for trout in unlikely desert surroundings. (Michael Greene photo) Editor's Note: Image was colorized in Photoshop and may not be factually accurate.
December 25, 2023
By Michael Greene
Editor's note: Flyfisherman.com will periodically be posting articles written and published before the Internet, from the Fly Fisherman magazine print archives. The wit and wisdom from legendary fly-fishing writers like Ernest Schwiebert, Gary LaFontaine, Lefty Kreh, Robert Traver, Dave Whitlock, Al Caucci & Bob Nastasi, Vince Marinaro, Doug Swisher & Carl Richards, Nick Lyons, and many more deserve a second life. These articles are reprinted here exactly as published in their day and may contain information, philosophies, or language that reveals a different time and age. This should be used for historical purposes only.
This article originally appeared in the July1984 issue of Fly Fisherman magazine. Click here for a PDF of the print version of "An Angler's Desert Oasis."
A trout stream flows through the barren desert landscape. Large numbers of trout often feed on the surface. The water is easy to wade and accessible from a paved highway which runs along its length. The brown, rainbow and cutthroat trout can be taken on small flies and fine terminal tackle. Is this a daydream? No, it is the San Juan River which flows through northern New Mexico.
The San Juan for a few miles below Navajo Dam is a river of abundant richness. The lake above the dam cools the warm silty water. Gone are the spring floods and fall droughts of the original watershed. The dam releases a constant flow of water into the riverbed. This steady flow of water at 43 degrees (F) creates ideal conditions for trout.
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The fish immediately below the dam are rainbow trout, between 12 and 24 inches long with emerald backs that camouflage them against the mossy bottom. Brown trout appear farther downstream as the water is warmed by the desert. The "Texas" hole, a deep run two miles below the dam, is known locally for its very large brown trout. The river below continues to warm and holds a mixture of brown, rainbow and cutthroat trout. The state of New Mexico , quick to recognize the San Juan's potential, in 1975 designated the first three miles below the dam "quality water." The fishing was restricted to the use of artificial lures. Fishermen could keep two fish each day both of which had to be over 16 inches in length. Starting April 1, 1983, this water was further protected. Fishermen must now use barbless hooks and may keep only one fish which must be over 18 inches in length.
Sadly, this rich fishery is short. The relentless heat of the desert soon claims back its own. Ten brief miles below the dam the river is laden with silt suited more for catfish than trout.
The heart of any trout stream is the food chain; and the San Juan is no exception. The unusual combination of hot desert sun and cool water creates vast beds of moss that spell out textbook conditions for midges. Hatching year around and reaching great densities, they provide a perfect source of food.
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The midges living and breeding in the San Juan's mossy bottom are primarily of the family Chironomidae. A typical midge hatch here lasts roughly two hours and on most days, the midges come off both morning and afternoon. Cloudy days often produce continual hatching from mid-morning until dark. The San Juan is indeed a river of midges, and more midges.
Prior to an actual hatch, the midge pupae get restless and their movement in and out of the moss beds attract trout, which feed greedily at the heads of the deeper riffles and runs. Once you locate a trout, try for it with a small pupa imitation. Cast upstream and allowed to go deep, the pupa will produce some of the fastest fishing of the day.
The midge pupae emerge by rising toward the surface and floating downstream. Many are trapped in the surface film and start to collect in the slower moving water, where the trout gather to feed. Near the surface in the slow water the trout are easily visible, with dorsal fins and swirling boils dotting the water.
The first encounter with this hatch may astonish even experienced anglers. Big fish are everywhere, most of them rainbows between 12 and 18 inches long. The occasional roll of an even larger trout is sure to quicken your heartbeat. Bue before you lose your head, pause to consider a plan of attack.
In spite of their illusory vulnerability these trout are wary and the hatch is hard to fish. The problem is one of competition from the many naturals in and on the water. The only compensation for the many naturals is the increased visibility of the trout.
Positioned upstream and to one side of a good fish, take a moment to examine the water. These trout are often selective to color. The midge pupae are small and in the water difficult to see. It is best to seine the water with a small net and capture a few pupae for examination. Determine the predominant color and tie on an appropriate pattern. I like to fish either a Griffith's Gnat or a Harvey's Horse Collar Midge. Clip the hackle on the Griffith's Gnat short and fish or in the surface film. The Horse Collar Midge may be left untreated and allowed to sink a few inches below the surface. The "naturals" being imitated are small so choose a fly no larger than a #18.
A natural drift is essential. On this flat water a downstream cast is the easiest way to achieve a long drag-free float. I improve my drift with a tippet at least 24 inches long and no larger than 5X or 6x in diameter. The "takes" usually will be gentle; once you feel the fish it is normally too late to set the hook. Greasing the leader and tippet to within one foot of the fly will help you see the take and will not unduly hinder the drift. Remember: A slight tightening is all that is needed to set these small hooks.
Anglers who are partial to dry flies can effectively switch during the latter half of the hatch. As the hatch progresses, the trout feed in the surface film. I have been unable to determine whether these fish are taking emergent pupae or escaping adults but no matter, as they will take a very small dry fly. The trout are hesitant and will inspect the dry fly more carefully than the pupae imitation. mailer flies, between #22 and #26, are often necessary. The dry-fly presentation also makes the trout more sensitive to the leader and to the slightest amount of drag. Long drag-free floats are an absolute must; and under many light conditions a 7X tippet is necessary. The trout's take, once induced, is confident and setting the hook is not a problem.
The midge hatch tapers off. Fewer and fewer fish break the surface. All activity seems to stop on the now-barren water. During this moment of stillness, I take advantage of the hiatus to prepare. The midge pupae will soon start to move in the riffles, another midge hatch will soon begin.
Bigger Flies, Bigger Fish The majority of San Juan trout over 20 inches long feed near the bottom in the faster runs and deeper riffles. "Regulars" on the river catch these bigger fish by using large nymphs and streamers. Woolly Worms and Muddlers are popular with different combinations of weight added to the flies and leader. The important thing is to get the fly near the bottom and to keep it there.
Two years ago my technique for nymphing the San Juan changed. The cause was a chance encounter with Ernie Sategna. I first noticed him nearby catching one large trout after another. He soon worked his way toward me. Once near he asked, "Why are you bothering with those fussy fish? They're too small anyway." I laughed and we fell into conversation. Ernie smoked one of his ever-present cigarettes. He watched me cast a small dry fly to the midging fish. We talked as fishermen will, and as so often happens on a river, we became friends.
Ernie, his cigarette finished, offered to show me his fly. It was a simple larvae pattern. He tied it with a brown yarn body, no ribbing, and a head of black thread. He said he no longer fished the midge hatch as nymphing the bottom was so productive. When I confessed my lack of success nymphing this river, he asked if I would like a few pointers. In my mind's eye I could still picture those half-dozen large trout he had caught with such apparent ease and eagerly said "yes."
We waded together to the head of a deep run. Ernie suggested I use a 9-foot leader tapered to a 3X or 4x tippet. He had me place a split shot about 18 inches above the unweighted fly. Ernie began to fish with quick upstream casts. He kept his fly near the bottom and covered a lot of water. The strikes were soft and a strike indicator was helpful. We fished together for a couple of hours and Ernie, of course, caught most of the fish. When he left he generously gave me a half-dozen flies and cried to encourage me with a final "stick with it."
The first few days it was easy to get discouraged. I had a technique I knew should work and a good fly, but none of this seemed to help. I did, thanks to Ernie, "stick with it", and can only say these fish are very fast. Do not expect to see any more than the briefest hesitation of the leader. In time you will begin to sense the "takes." You may never become as proficient as Ernie, but you will find chat on the San Juan this is the best way to catch the most, and the biggest, fish.
The "Texas" Hole If large brown trout are your first love ignore all chat has been said and go directly to the Texas Hole. It is full of brown trout, many of which weigh over 10 pounds. The Texas hole is actually a long deep run which follows the natural curve of the river. The main channel is deep, fast and perhaps 30 feet wide. It is necessary to fish with either a high-density sinking-tip or heavy weight on the fly and leader. Continual mending is required to give the fly time to get to the bottom. This is cough fishing for trophy trout.
An alternative is to cross the river. Some of the largest trout lie in the water along the far bank, and once there you can fish directly into this slower band of water. The far bank is a combination of cliff and large rocks, so moving about is difficult. Bring a longhandled net. Attempting to land these large fish from the rocks creates real challenges. Late afternoon completely changes this hole. The big browns come to feed in the shallow water along the near side and their wakes line the stillwater surface. Streamers work well. The best method is to spot a moving fish and lead him with your cast. The last hour before dark can produce some memorable moments as these five-pound-plus browns chase your streamer.
To find the Texas Hole, look for a Catholic church two miles downstream from the dam. The church, visible from the highway, serves as a local landmark. It signals the turn into a paved parking lot provided by the state of New Mexico, a place to park your vehicle, put on your waders and assemble your gear. The parking lot is about 50 yards of flat walking from the river.
When you reach the river go upstream for the rainbows and downstream for the Texas Hole and the brown trout. Below the Texas Hole the protected water ends. The river downstream of the "quality" water continues to hold large trout. In addition to some of the very biggest fish this water also boasts a population of large cutthroat trout and also provides a habitat for mayflies. These mayflies, when they hatch during the summer months, provide exciting dry-fly fishing.
The river is remote and difficult to reach. The nearest towns are Aztec and Bloomfield, both approximately 30 miles from the river. Out-of-state fishermen can fly to Farmington, New Mexico or to Durango, Colorado. Farmington, a little over 40 miles away, is the slightly closer airport.
Michael Greene is a freelance writer making his debut in FFM.
This article originally appeared in the July 1984 issue of Fly Fisherman magazine.
