Western Tailwater Fishing

Fishing a tailwater river will always be defined by an August day I shared with my wife on the Bighorn in the late 1980s. After several evenings of being forced to listen to stories of almost embarrassingly productive fishing, she was convinced to join me for a day. We hopped into my little 8 foot rowboat, drifted a few hundred yards from the afterbay ramp, and parked just downstream from a submerged rock ledge where I had seen fish scatter from the boat’s shadow the days before.

Expecting hatches of Pale Morning Dun mayflies later in the morning, I tied on a small Pheasant Tail nymph, using an Elk Hair Caddis dry fly as an indicator. Since she was just learning to fish with a nymph and indicator, I played the helpful instructor and led her cautiously upstream until I spotted a trout tail, finning slowly over the submerged ledge. I made a short cast, leading the fish just enough to allow the nymph to reach his depth, and watched both the drifting dry fly and the fish’s tail. When I saw the tail scoot upstream and the dry fly stop, I lifted the rod, and set the hook on the first fish of the day.

Leading the fish downstream and netting it, I handed over the rod and told her to repeat the performance. She did. So did I. Over and over and over again. After a while, we took turns with the rod, often hooking several fish without moving our feet, then taking a step upstream and repeating the performance.

Once, when my attention wandered to a passing songbird or driftboat, she muttered, “I don’t see my dry fly anymore.”

“Strike!” I yelled. On cue, a nice rainbow came rocketing out of the depths, the nymph tucked neatly into a corner of his jaw.

We spent several hours in this short stretch of water, catching dozens of fish. We ate a sandwich, caught some more fish, toasted the summer day with a cold beer, then caught some more fish. Just when I started to think about the idea of making the short hike back to the put-in rather than finish the float, we looked up to see our car disappearing from the parking area.

“Well,” I said, “our car is headed downstream, so I guess we had better do the same.”

What is a Tailwater?

In angler’s jargon, a tailwater is a fishery whose source is the release from a manmade dam, rather than the snowmelt that creates a freestone stream or the spring flows of a natural spring creek. If the releases come from the base of the dam, the cold water from the bottom of the reservoir will support a trout population.

In some cases, a dam may produce a tailwater influence on an existing trout fishery, moderating flows and water temperatures. Examples include Montana’s Beaverhead and Madison, and even the famous Railroad Ranch section of the Henry’s Fork in Idaho. More remarkable are tailwater streams that did not support a coldwater fishery before the dam was built – Montana’s Bighorn, New Mexico’s San Juan, and Utah’s Green were once all warm, muddy prairie or desert rivers, not the clear trout streams we know today. Conservationists may warn us that “they aren’t building new trout streams anymore”, but there were quite a few built back in the 50’s and 60s. The list of other western tailwaters include many of the best known rivers in the region: the South Platte and Frying Pan in Colorado, the Missouri in Montana, the North Platte in Wyoming, and the Provo in Utah.

So what makes tailwater fishing different from other trout fishing? Like a natural spring creek, a steady supply of cold water creates a stable environment for both trout and the aquatic insects and other invertebrates they prey on. Because most dams in the West were constructed for irrigation storage, flood control, or power generation, they were built on larger rivers, and the size of the tailwaters they create would swallow most small spring creeks. Big tailwaters often support mind-boggling numbers of both bugs and fish, and the fish grow quickly to large sizes in this food-rich habitat.

This difference in scale from most other trout streams also results in different feeding behavior. During heavy hatches, the fish gain a measure of security by gathering in large numbers to take advantage of the food supply. A “pod” of hundreds of trout slurping away at the surface can convert an angler into a tailwater aficionado in a hurry.

“If you build it, they will come”

The down side of tailwater angling is that the numbers of big fish also draw lots of angling pressure. Tailwaters appeal to beginners because, even with minimal skills, they can catch a reasonable number of good-sized fish (especially with the help of a guide). More advanced anglers flock to tailwaters for the consistent dry fly fishing and the chance to catch large fish. Don’t kid yourself—we flyfishers may talk about the esthetic pleasures of the sport (usually at the end of a fishless outing), but everybody likes to catch fish. And a whole bunch of big fish is even better.

The popularity of tailwaters is due to a number of factors in addition to the productive fishing. Many tailwaters are found near population centers—electric power and irrigation water are not needed in wilderness areas—so some of the angling pressure lives nearby. Good roads are needed for maintenance workers as well as recreational users of the reservoir above the dam, so access to most tailwaters is straightforward.

Most tailwaters are also found at lower elevations than a classic mountain trout stream, and milder weather conditions allow long growing seasons for fish and long fishing seasons for anglers—mid-winter fishing has become popular on many tailwaters. Such lower elevation streams often exhibit a relatively flat channel with fine gravel or silt bottoms, making for easy wading.

With all of these positives comes the reality that you are not likely to have the place to yourself. Although crowding sometimes leads to “combat fishing”, with guides and anglers competing for the best spots, an adjustment of attitude is usually enough to keep things in perspective. Think of a tailwater as an amusement park for anglers, rather than a pristine trout stream, and things 

will fall into place. Sharing the stream with lots of people might not be ideal, but as long as you can find a place to fish, the fishing itself is not much affected by the extra anglers. Complaining about the crowds on a tailwater is like going to Disneyland and bitching about all the little kids on the teacup ride. Tailwaters, because they can support so much fishing activity, also act as a relief valve, taking pressure away from more sensitive fisheries.

Fly Innovation on Tailwater Fisheries

Tailwater fisheries have been the birthplace and proving ground for many of the most innovative fly patterns of the last twenty years. With lots of anglers on the water, there is a lot of experimentation going on, and there are so many fish that almost any new pattern will catch at least a few of them. Young guides in Fort Smith or Dutch John, spending their late night hours at the tying vise (since they don’t have much opportunity to indulge in other vices), have been known to come up with very unorthodox fly patterns.

But for a pattern to really catch on, it has to prove itself with lots of anglers. On a busy tailwater, a new pattern can be tested by a large number of people and with modern communication and travel, a local killer pattern can become well-known almost overnight.

Tailwater fishing has introduced many non-traditional patterns because there are some foods found in these streams that are not as important in a typical freestone stream. The San Juan Worm represents annelid worms (or midge larvae, if tied in small sizes) and the Bighorn Shrimp represents scuds or other crustaceans (though some argue that bright scud patterns are really egg imitations in disguise.) The Chernobyl Ant was designed as a cicada imitation for the Green River, but anglers all over the world have found this to be an effective attractor pattern as well.

Intense fishing pressure does cause changes in the fish’s feeding behavior. In particular, anglers find that scaling down the size of the fly can be a good tactic when trying to fool fish that see lots of artificials. When the Bighorn first opened to fishing, a #6 San Juan Worm or #10 Bighorn Shrimp were two of the flies of choice. Now, anglers are more likely to use a #16 worm pattern or a #18 or 20 scud to be successful. Similarly, twenty years ago, a #4 Girdle Bug was a typical fly on the Beaverhead; though these big flies still work on occasion, you will find the regulars fishing #18-22 Pheasant Tails or a tiny midge pupa pattern, even in deep, fast currents. Picky fish on Colorado’s South Platte made tiny versions of the Brassie and RS-2 Emerger famous.

Another fish response to angling pressure is what I call “pattern fatigue”, when the fish simply begin to refuse a pattern they see too often. Although they continue to feed on the same natural foods, the fish respond better to artificial flies that are even slightly different. Flies incorporating a bit of flash have become very popular. Whether they act as attractors or imitate the appearance of real foods, patterns like the Disco Midge or any of the Flashback nymphs have become standards on tailwaters.

Managing Tailwater Fisheries

The resources of tailwater fisheries are valued by many interest groups. Phil Gonzalez, a regular on the Bighorn since 1969 and now the owner of the Bighorn River Lodge, discovered first-hand just how highly those resources can be valued.

In April of 1978, Phil was floating the river with his friend Pat Wright. Fishing the “Glory Hole”, they noticed there seemed to be an unusual amount of activity on the river that day. Wallace Redstar, a warden for the Crow tribe, stopped and told them to follow him down the river. Pat knew warden Redstar, and told Phil that something unusual was up, and from his tone of voice, he knew Redstar meant business.

When they got to the “Pipeline Hole”, it became clear that the wardens were closing the river to fishing and sending anglers packing. Larry Mayer, a photographer for the Billings Gazette, recorded Phil’s removal from the river at the point of a shotgun muzzle.

In the ensuing legal actions, the courts ruled that even though the river flows through Crow reservation lands, the river itself was open to the public. When the river was officially reopened for fishing in August of 1981, a group of Crow tribal members attempted to set up a roadblock at the Two Leggins Bridge. Law enforcement personnel were able to defuse the situation, but this history of access issues on the Bighorn points to the challenges faced by those who manage these fisheries.

Although restrictive regulations have played a critical role in restoring quality fishing on many streams, they are less important on fertile tailwaters. Catch-and release is now the norm, and in studies done on the Bighorn in the early 90s, it was determined that less than 3% of the fish caught were actually taken home. Ken Frazer, the fisheries biologist on the Bighorn for Montana Fish, Wildlife & Parks, points out that natural mortality on the river is at least 30%, so angler harvest is not a critical issue.

More important is the water supply that creates these rivers. “On the Bighorn,” Frazer says, “our main objective is in maintaining flows. Whatever water there is, is filled with fish flesh. As long as we have water, we’ll have plenty of fish.”

A key point in the management of tailwaters is that the dams that create these fisheries were built for humans, not for fish. The agencies that control operation of the dams often see fishery resources and angling as incidental to the “real” needs of generating power or storing irrigation water. The popularity of tailwater fishing has created a large constituency, and the economic benefit of angling tourism needs to be considered alongside the needs of agricultural producers and electrical consumers. As with most resource issues in the modern West, the key is to find common ground and management strategies that will accommodate the needs of various interest groups.