Boating News

A Beginner’s Guide to San Juan River Fly Fishing

Because this is a beginners guide, I am going to try and keep everything as simple as I possibly can.  Simplicity is a great asset on the San Juan, one that many people don’t consider.  Keeping it simple will quicken the learning process.  Above are some quick link buttons that will take you to our current San Juan River Reports, flow info, guide info, fishing licences, and a map (or just scroll down for the map).  These will help you catch fish (and not get arrested) on the San Juan River.

Before we get into it, let me just state that if you really want to up your San Juan River game, take a trip with one of our experienced guides.  A guided day on the San Juan will drastically reduce your learning curve and make sure you are getting into fish a lot sooner.  Our guides spend hundreds of days on the San Juan each year and the knowledge gained through years of rowing clients down the river will be imparted onto you throughout the day!

Give us a call if you would like to book a guide trip at 970-385-4081 with one of our guides or shoot us an e-mail at [email protected]

So let’s get started; for those who know absolutely nothing about San Juan River fly fishing, here is a primer:

Where is the San Juan River?

Northern New Mexico.  A 60 minute drive from Durango!

What makes the San Juan so special?

The San Juan River in New Mexico is a tailwater flowing out of Navajo Dam from the bottom of Navajo Reservoir.  This makes for a fairly consistent year round outflow temperature.  Consistent year round water temps make for year round fishing.  The magic of tailwaters!

When the river was impounded in 1962, the water temperature mixed with the nutrients in the river made the perfect storm that resulted in a bug factory.  Trout were stocked and immediately began to thrive.  With nonstop food, trout eat constantly…and grow large.  This section is low-gradient and easily floatable year round.  Add to that, the beautiful desert canyon scenery, and it becomes a very unique fly fishing experience.  The state of New Mexico realized this and the first three miles of the tailwater are a part of Navajo State Park and incorporate special catch and release fly and lure only regulations.

To put it simply, it is like a large spring creek fishery in the desert.

Battling the elements can pay off. Jake with a sweet San Juan brown.

The San Juan is a great year-round fishery, even in the midst of a winter snow blitz

Equipment Needed for San Juan River Fly Fishing

Waders and Boots- You want waterproof, breathable waders…and you don’t want leaks.  Even in the dead heat of summer, the river is cold.  Leaky waders can make a good day go bad real quick when you have to get out of the water every five minutes to warm up.  While the San Juan this isn’t the most technical wading ever; the bottom of the river is covered in slick snot-like moss.  Stepping on a slick rock is a quick way to take a dunk.  Good boots are a must and cleats or aluminum bars help immensely.  Our guides are on the San Juan a lot, and because of this often choose Simms Bootfoot Waders as they are quick to get on and immensely warmer.

Clothing – With the cold water, you will want to wear warm layers on your lower half at all times.  Wicking layers and warm merino wool socks will keep your lower half happy in all four seasons.  Avoid cotton.  If it is the winter, dress your upper half appropriately in layers and always be prepared for rain or snow with a waterproof rain shell.  During the dog days of summer; cool long sleeve shirts, caps, and Buffs will help keep your skin un-burnt.  It’s an interesting experience to have the top half of your body sweating in the summer heat and the bottom half of your body needing an extra layer while wading in the cold water.

Fly Rods – Since this a trout fishery, 4 to 6 weight rods are standard.  The best all around fly rod is a 9 foot 5 weight.  We like to fish longer rods up to 10 feet to assist with nymphing, but it is not necessary.  Our favorite rod for the San Juan is a 9′ 6″ 5 weight Scott Radian.

Fly Reels – A reel matched to your rod and line weight with a solid drag is important.  Since you will be fishing light tippet, a solid drag is key to keep you from breaking off any bigger fish.  Our favorite reels include the Ross Reels Animas and the Sage Spectrum LT.

Fly Line – Line is often personal preference, BUT we recommend a floating line matched well to your rod’s action and weight.  The SA Amplitude Trout is a great choice and works with a variety of applications when nymphing or fishing with dry flies.  Our personal choice is actually the Rio Single Hand Spey line as it is an incredible roll casting line with a nymph rig, and mends fantastically well

Leaders – More often than not, you will use a 7.5′ or 9′ 5x leader.  Rio Powerflex Plus leaders are often our choice.

Tippet – Tippet is actually pretty important for San Juan River fly fishing.  The trout have become accustomed to the presence of fisherman on the river…as well as their drifting flies.  To have the best possibility of catching fish, fluorocarbon is a must.  We have found in the past year that Trout Hunter Tippet is by far the best tippet to use.  Trout Hunter is strong and stretchy and helps keep you from breaking off hard fighting fish.  5.5x and 6x Trout Hunter is our favorite for the San Juan.

Polarized Sunglasses – This should be a no brainer, but people still forget this fact.  Polarized sunglasses help you see the fish.  If you can see the fish on the San Juan, you are half way there!  Plus it keeps hooks out of your eyes from wayward casts.  If your glasses are polarized, they will work; HOWEVER we have found the Smith Chromapop series of lenses to be by far the best lenses we have ever fished.  These lenses work in a variety of lights, especially at dusk and dawn.

Accessories – You are going to want: forceps to remove flies from fish and crush barbs on hooks (the San Juan is a barbless, 2 fly max fishery), nippers (don’t use your teeth), indicators, a good assortment of split shot, fly floatant for when trout are sipping dries, drinking water, lunch, a vest or pack to carry all your gear, and sunscreen.  Finally you will want a leader straightener, which will ensure your leader is straight so you are detecting the most subtle strikes when nymphing and are able to set the hook quickly without any slack in the leader.



Our Juan boxes can get a little crazy, you may want to keep yours a little more simple.

The most frequent question we are asked about San Juan River fly fishing is “What flies are working?”

Small flies are working.

To expand on that, small midges and annelids are what the fish are eating.  Now of course, there are more food sources than these two; however 90% of the time 90% of the fish you can catch will be on these two imitations…figure out that math!

Rather than write an entomology tome that lists all species and subspecies of bug and insect that resides in waters of the San Juan tailwater along with it’s corresponding imitation; I will keep this as simple as I can with two lists: one list of the trout food most often spotted in the San Juan, and another with the flies I would use.


The San Juan River contains some substantial food sources for trout.  They are:

  • • Midges – The staple, year round food source.
  • • Blue Winged Olives – Mostly found in the spring and fall, these can often be found below Texas Hole
  • • Annelids and Aquatic worms – Another year round staple that trout are constantly feasting on close to the dam
  • • Leeches – Fish will eat leeches year round on the San Juan, especially in the fall and winter.
  • • Trout Eggs – A great attractor point fly for your nymph rig, works year round but best in the spring and fall.
  • • PMD – Found in the lower stretches in summer.
  • • Caddis – Same as PMDs, most often found in the lower stretches throughout summer.
  • • Hoppers – Closer to the dam, trout will not target hoppers as frequently, but as you make your way down river (especially in the lower water) hoppers become a great fly of choice in the summer.
  • • Large Flying Ants – Large ants will wash out of the cliffs above the river during the first monsoons of summer in the millions.  Fish go nuts for these ants at this time, but they can be found all summer along the banks.
  • • Baitfish – Baitfish are more productive in the lower stretches, including sculpins and fingerling trout.


If I was limited to no more than ten fly patterns in my fly box for the San Juan, they would be these (Hover over image for more info):

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