With an eerie predilection for the future, Spanish explorer Juan Rivera named the modest stream he found draining the western flank of the San Juan Mountains La Rio de las Dolores, the river of sorrows. Two hundred years later, the river still has reason to be sorrowful. Few streams in the western United States have experienced such a history of misinformation as the Dolores.
The Dolores made its reputation as one of the West's finest tailwater fisheries in the mid-eighties when cold water first flowed from McPhee Reservoir into the river channel. McPhee Dam was constructed to deliver irrigation water to the rolling hills of southwestern Colorado near Cortez. Eying the success of the tailwater below nearby Navajo Dam on New Mexico's San Juan River, Colorado Division of Wildlife (CDOW) was quick to establish trout in the river below the dam. Fingerlings planted in the river in 1984 grew quickly in the rich waters and by the next year anglers found an exciting catch-and-release fishery from the dam to Bradfield Bridge twelve miles below. By 1986, the river's fame had spread throughout the west. But the Dolores fishery was just a byproduct of the construction of McPhee Dam. The dam and reservoir were to be managed primarily for agriculture. For the first two years of the operation of the dam, the irrigation delivery system was incomplete. With little water extracted from the reservoir to head to the surrounding bean fields, and with an unusually high amount of precipitation, plenty of water flowed into the river. From 1984 to 1986, flows in the Dolores averaged 250 cfs. The Dolores had yet to experience a normal year.
The management plan stated that water in the reservoir was to per shared proportionally by irrigation demand and the river. Minimum flows in the river for August were to be determined in March of each year by estimating the reservoir level that would occur on the last day of June. Depending on the estimate, late summer flows were to be set at either 78 cfs, 50 cfs, or 20 cfs. In 1987, a prolonged drought brought the reservoir levels down and river flow was reduced to 78 cfs where it remained for the better part of two years. The trout population in the Dolores shrank accordingly. By 1989, the population had stabilized at lower levels, and fishing was good, but not the same as in the boom years. Disaster struck in 1990 when low precipitation created a 20 cfs year. For more than three months, flow remained at 20 cfs, far too little to maintain the trout. A concerted effort from CDOW, Trout Unlimited, and local residents got flows up to 50 cfs, but not before about 50% of the trout in the river were lost.
Reacting to the disaster, the river management team developed the pool management concept as an interim plan. In pool management, minimum flows were rejected in favor of a variable flow system that permits less water to flow into the Dolores in winter as a trade off for higher flows in summer. Today the Dolores again has a stable trout fishery featuring good-sized brown, rainbow and cutthroat trout. Browns can go up to 18 inches, and the rainbows are fat. As it has been since the beginning, the first 12 miles of the Dolores below McPhee Dam is managed as fly-and-lure-only water and all fish must be immediately released back to the water. Below McPhee, the Dolores flows through a flat-bottomed sandstone canyon of incredible beauty. The sand of the white cliffs was deposited as dunes back when Tyrannosaurus and his buddies ruled the west. The sloping canyon walls above the cliffs are covered with juniper, pi¤on, and oak, and turn to fire in the fall when the cottonwoods along the river turn yellow. The river itself ranges from 20 to 35 feet in width. Much of the river is shallow riffles and slow bends. The low gradient of the stream produces little pocket water or few deep spots. Holding water for trout is scattered during summer flows. Although the river is easy to wade and offers plenty of room for maneuvering into position, you must cover a long stretch of river in the course of a day.
Compared to many western rivers, the Dolores is user-friendly. It doesn't take a monumental effort to wade through the shallows to get into position for casting. You can always select and reach the perfect spot to make your cast. The typical tailwater effect on water temperature is only felt for the first few miles downstream from the dam, so there is no need for neoprene waders. Hip boots will see you through most situations on the river, and in summer, wet wading is the ideal way to fish. Light- to mid-weight rods are best suited for this tailwater. Three- to 5 weight outfits are ideal. Because the river is not fast nor deep, there is no need to cast weighted leaders or heavily weighted flies and eight-and-a-half-to 9-foot rods are adequate for all by the windiest of days. Hearsay brings most fishermen on the Dolores up close to the dam where the best fish are supposed to lie. The truth is that fine fish are found throughout the river from the dam down to all the way down to Bradfield Bridge. If you feel crowded at the upper end, consider dropping down a few miles. Twelve miles of river offers a lot of space and you should have little trouble finding a place of your own. Going mid-week will increase your chances of having a long stretch of river to yourself. It should go without saying but you should always give other anglers plenty of room and not follow too closely. Releases from McPhee Dam run about 2500 cfs from late April to mid-June. At this time the river is off color and considered dangerous to fish. The river fishes best for several weeks of June and early July immediately following high water. The shallow water of summer heats quickly and mid-summer fishing slows, particularly around mid-day. Conditions are again favorable in the fall when mid-day is the time to be on the water. The Dolores is a fine dry fly stream. In the slow and lazy currents of the river, fish get long looks at a fly before deciding whether or not to take it. Under most circumstances anglers try to match the hatch and fish to rising trout. Hatches are thickest in the miles just below the dam and become sporadic lower down. In the shadow of the dam, fishing is often challenging because of the sheer numbers of insects on the water. Blue-winged Olives provide most of the action through the year. Hatches occur on most days during in spring and fall, but summer hatches are not uncommon, particularly on overcast days.
The insects range from size 18 to 24. A popular variation of the standard BWO pattern is tied with an olive thread body and a parachute blue dun hackle tied on a clipped white calf tail post. Small olive or dark colored nymphs are equally as effective as the dry fly during and after the hatch. The size of the insects decreases as the year wears on. By late September, the insects on the river are small--a size 24 Blue-winged Olive is the main hatch through November. Pale Morning Duns hatch in mid-summer from 11 a.m. to the early afternoon. The light-colored mayflies are well imitated with a Light Cahill or a simple yellow-tan parachute fly size 16 to 18. When no visible hatch is occurring, fish the Dolores with terrestrials. Ants and beetles are consistent fish-takers beginning in July. Cast the flies tight along the banks and under overhanging vegetation. Use a size 12 pattern early in the year, reducing the size to 16 by September. Hopper season runs from August to mid-fall. Large hopper patterns in sizes 6 to 10 are particularly good fished along the banks. It is not always easy to catch trout on the Dolores. Experienced anglers tend to love the challenge of the Dolores; novice anglers often have a tough time, but don't seem disappointed.
Excerpt from "Fly Fishing Southwest Colorado" available at Duranglers in Downtown Durango.