Fly Fishing the San Juan River

John Tavenner

Fly Fisher/Guide/Fly Tier/Writer

★ ★ ★ ★
John Tavenner a professional guide on the San Juan River in New Mexico knows every inch of this trophy producing tailwater. Listen in while he tells his secrets of fly fishing for big trout with little bugs.

John Tavenner
Fly Fishing the San Juan River
John Tavenner Fly Fishing the San Juan River

Learn more about John Tavenner...

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Imagine yourself fly fishing on 4.25 miles of quality tailwater surrounded by over 80,000 trout. If you’re looking forward to having your best catch yet, the San Juan River in Mexico is the place to be. It is one of the finest tailwater fisheries that you can probably find anywhere in the world.

Expert fly fisher John Tavenner first fished the San Juan River in 1985 and fell in love with it. He started guiding fly fishers in New Mexico that same year. He became a full time guide six years later. John has 30 years of combined experience in fly fishing and fly tying, having started to fly fish for rainbows and cutthroat at a young age of 11. Today, he is a professional guide, fly designer, author, and lecturer. He is a featured tier with the Pacific Fly Group and has developed many fly patterns which are now popular with experienced San Juan fly fishers. He wrote the section on the San Juan River for the book, A Fly Fisher's Guide to New Mexico by Van Beacham. He and his wife, Monica, started Sandstone Anglers in 1999 and the Aztec Chamber of Commerce subsequently named Sandstone Anglers "New Business of the Year".

The San Juan River is one of the best known rivers in the United States and the largest river in Mexican state of Nueva León. It is located in the northwest corner of New Mexico near the Four Corners where the four states meet. The San Juan originates in Southwestern Colorado up in the Wolf Creek Pass area. Below the Navajo Dam there is approximately 15 miles of fishable river. The upper stretches will hold anywhere from 10,000 to 15,000 fish per mile.

The dam was created in 1962 and the tailwater started containing trophy trout in 1966. The reservoir is close to 300 feet deep and the water is taken out at about 250 feet so the temperature of the water is 42 degrees year round.

The San Juan is a good place to fish every month of the year, although the lake turns over every year in the middle of December through most of the spring. At this time, the water is not as clear as it usually is after the fish have their high spring releases. In June, the water goes down and becomes very clear through the fall and into early December. John’s best time for fishing in the river is in November and the time frame from mid-June through mid-July, although September and October are two of the most popular months for fishing.

The primary fish in the river is rainbow trout. In fact, the San Juan River is deemed as the best rainbow trout fisheries in the US. They outnumber the brown trout, although the browns toughed out the drought years in the early 2000s. At that time, the browns took a stronghold in the river and a lot of sections in the river have about 30% to 40% brown trout.

The average fish in the San Juan River is anywhere from 15 to 18 inches. There are also a few in the 18 to 21-inch class, but not so many fish grow beyond that. Rainbows get much larger than browns especially in the special trout water in the upper four miles of the river since there is not a lot forage fish for browns to feed on.

The San Juan Rriver has around 15 miles of fishable water – the last eight miles passes through a private land where you need to have permission or pay-access to fish the area. The upper four miles is known as the special trout water or the quality water stretch. When you get near the dam, you have to go through a lot of series of riffles with long pools.

There is a lot of slow moving water with a spring-creek-type feel to it. Although there are a lot of riffles, the coldness of the water promotes midges so fishermen can get a lot of fish in the slow moving water. There is a run that you have to pass through called the Cable Hole which is a big, long deep run. The tail out is called the Upper Flats, which is a big, long, calm pool. There are also some braided channels that last a quarter of a mile at normal flows which hold an incredible amount of fish. Where they all meet is called the Texas Hole, a half mile long stretch which holds 10,000 fish. Outside the Texas hole are channels that branch off on the south and north side of the river. When those channels come back together, they form an area called the Lower Flats, a large broad, shallow riffle which is very popular with waders. It narrows up and forms the Lunker Alley and creates the Baetis Bend and then a long, calm, deep pool known as Death Row. It is named such because anglers who row through it in 30-mile winds thought they were going to die.

If you want to fish in the river, John recommends a 4- or 5-weight rod, and an 8-1/2 to 9-foot since you will be doing a lot of nymph fishing. This allows you to control the line, which is very important. Longer rods will help you control the line. During normal flows, a 7-1/2-foot 5x leader works best together wil a 6x fluorocarbon tippet for the flies.

Aside from midges, other types of hatches in the river include caddis and Baetis mayflies.

Listen to our full interview with John Tavenner and learn more about fly fishing on the San Juan River in Mexico.


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