San Juan River Fly Fishing: New Mexico's Year-Round Tailwater Trophy Factory

Quick Reference

What	When	Key Numbers
Quality Waters	Year-round (fall best for crowds)	15,000 trout/mile; 17" avg; 3.75 mi C&R section
Ideal flows	300-500 CFS typical	42-46°F water year-round; fishable all seasons
Fly sizes	Midges #20-28; BWOs #20-24	6X-7X tippet essential; single barbless hooks
Texas Hole	Arrive before sunrise weekends	Most fish; most crowded; best hatch activity
Guided trips	Worth it for first-timers	$400-500/day; Abe's; Fisheads
License	NM fishing license required	Check current regulations at wildlife.state.nm.us

Before You Go

You've heard the stats: 15,000 trout per mile. Fish averaging 17 inches. The San Juan River below Navajo Dam is, by the numbers, one of the most productive trout fisheries in North America.

But those numbers hide something important: these fish have PhD's in fly refusal. They've seen every pattern in your box, presented by thousands of anglers before you. The San Juan will humble you - and that's precisely why serious fly fishers keep coming back.

This isn't a place where you tie on an elk hair caddis and start catching fish. It's a place where you learn to fish size 24 midges on 7X tippet and celebrate when you finally crack the code.

The San Juan's crystal-clear tailwater demands precise presentations and small flies.

Why the San Juan is Different

The Navajo Dam, completed in 1963, transformed the San Juan from a warm, muddy desert river into a cold-water trout factory. Water released from the bottom of the 402-foot dam stays a constant 42-46°F year-round, creating ideal conditions for rainbow and brown trout.

The result is a tailwater with staggering biomass. The 3.75 miles of Quality Waters below the dam hold over 80,000 trout - mostly rainbows, with a healthy population of browns. These fish grow fat on a diet dominated by one thing: midges.

What makes the San Juan special:

• Consistent flows (typically 300-500 CFS) year-round
• Water clarity measured in feet, not inches
• Year-round midge hatches - sometimes multiple per day
• Blue-winged olive hatches in spring and fall
• Fish that have seen it all and require technical presentations

The Quality Waters: Where to Fish

The first 3.75 miles below Navajo Dam are designated "Quality Waters" by New Mexico Game and Fish. This is catch-and-release only, artificial flies with single barbless hooks. Two flies maximum.

Texas Hole

The most famous (and crowded) spot on the river. A narrow gap funnels swift current into an 8-foot-deep pool where trout stack up in impressive numbers. The warmer water here supports more diverse insect life than the upper reaches.

• Parking: 3.8 miles upstream from the Hwy 173/511 intersection
• Why fish here: Highest fish concentration, best mayfly activity
• The catch: Gets crowded, especially weekends. Arrive before sunrise for the best spots.

Upper Flats

Upstream from Texas Hole, the river spreads out and slows down. This is where you'll find some of the biggest fish - and the most technical fishing. Shallow, clear water means spooky fish that demand long, fine leaders and perfect drifts.

• Parking: 4.4 miles upstream from the intersection
• Why fish here: Trophy potential, less crowded
• The catch: Harder wading, more technical presentations required

Lower Flats & Simon Canyon

Below Texas Hole, the river widens and meanders. More caddis activity here than upstream, along with scuds and aquatic worms. The Simon Canyon section is the warmest water in Quality Waters, supporting the most diverse bug life.

• Parking: 2.7 miles upstream from the intersection
• Why fish here: More insect variety, solitude
• The catch: Longer walk from parking, fewer fish per mile than Texas Hole

San Juan rainbows average 17 inches, with plenty of fish pushing 20+.

Understanding San Juan Flows

Unlike freestone rivers, the San Juan's flow is controlled by Navajo Dam releases. This means consistent, predictable conditions - but you still need to know what the numbers mean.

Flow (CFS)	Conditions
Under 250	Low water - fish concentrated, easier wading, more pressure on fish
300-500	Ideal range - normal operations, fish spread out, good wading
500-800	Higher water - deeper wading, fish pushed to banks
Over 1,000	Spring peak releases - difficult fishing, limited access

Current flows run around 300-350 CFS most of the year. Spring environmental releases can spike to 5,000 CFS for up to 60 days, mimicking natural conditions for native fish recovery downstream.

Check real-time San Juan River flows near Archuleta before you go.

The Flies That Actually Work

Forget your standard trout box. The San Juan is midge water, and you'll fish smaller flies here than anywhere else.

Midges (Year-Round, All Day)

The San Juan has reliable midge hatches every day - typically one mid-morning and another in the afternoon. These are your bread-and-butter flies:

• Midge Larva (#22-28, black, cream, olive) - dead drifted deep
• Zebra Midge (#20-24) - the universal San Juan pattern
• RS2 (#22-24, gray) - poly wing emerger that works as both nymph and dry
• Black Midge Cluster (#18-24) - for fish eating adults on the surface
• Griffith's Gnat (#18-22) - when fish are on mating clusters

Blue-Winged Olives (Spring & Fall)

When baetis hatch on overcast days, the fishing can be exceptional:

• Parachute Adams (#20-24, gray) - simple and effective
• Sparkle Dun (#22-24) - emerger pattern
• Pheasant Tail (#18-22) - standard nymph for baetis

Attractor Patterns

Not as critical here as other rivers, but worth having:

• San Juan Worm (#14-18, red, orange, tan, brown) - the river's namesake pattern
• Scuds (#16-18, olive, tan) - especially in Simon Canyon
• Egg patterns (#16-18, peach, pink) - work year-round

The Tiny Fly Problem

If you've never fished #24-28 flies, prepare for frustration. A few tips:

1. Use fluorocarbon tippet (6X-7X) - it sinks and is less visible
2. Keep your flies clean - algae buildup kills the drift
3. Carry a magnifier - you'll need it to thread these hooks
4. Use a small strike indicator - standard bobbers spook fish in this clear water

Seasonal Patterns

Spring (March - May)

Baetis hatches kick into gear on cloudy afternoons. Look for rising fish in slower water, especially on overcast days. As water temps climb, fish become more active and willing to chase streamers.

Best approach: Morning nymphing with midge larvae, afternoon dry-fly fishing during BWO hatches.

Summer (June - August)

Peak tourist season brings crowds, but also the best dry fly action. Terrestrials (ants, beetles, hoppers) work in Simon Canyon. Midge hatches continue reliably. Water temps stay cold, so fish remain active all day.

Best approach: Early mornings for solitude, late afternoons for midge hatches. Fish early or miss the crowds.

Fall (September - November)

Many consider this the best time to fish the San Juan. Crowds thin, cottonwoods turn gold, and fish feed aggressively before winter. Baetis hatches return with intensity.

Best approach: All-day fishing is productive. September is prime time for dry flies.

Winter (December - February)

This is when you'll have the river to yourself. Water temperature stays constant, fish still eat, and the crowds disappear. The cold air doesn't mean cold water - the tailwater stays in the mid-40s year-round.

Best approach: Nymph deep with midge patterns. Fish are slower but definitely feeding. Heavy tippets, big flies, patient presentations.

Techniques That Work

Nymphing (The Primary Game)

Most of your fish will come subsurface. The standard San Juan rig:

1. Lead fly: San Juan Worm or larger midge (#18-20)
2. Dropper: Small midge pupa or RS2 (#22-26), 12-18" behind the lead
3. Tippet: 4X to the lead fly, 5X-6X to the dropper
4. Indicator: Small, visible, easy to move for depth adjustments

Key technique: Get your depth right and let the fly drift naturally without drag. Mend constantly. These fish have seen a million bad drifts.

Euro Nymphing

The San Juan is excellent euro nymphing water. The clear, consistent flows let you read fish reactions. Use 10.5-11' 2-4 weight rods to reach across currents without putting line on the water.

Dry Fly Fishing

When fish are rising - and they do rise - the dry fly fishing can be outstanding. Keys to success:

• Long, fine leaders: 12' or longer, ending in 6X-7X
• Mono tippet (not fluoro) - floats better
• Precise casting: Put the fly in the fish's feeding lane, not 3 feet away
• Watch your shadow: These fish spook at everything

Gear Recommendations

Rod: 9' 4-weight or 5-weight, fast action for mending and distance Alternative: 10-11' euro nymphing rod (2-4 weight) for tight-line techniques

Reel: Simple click-and-pawl or disc drag - you're not running fish into the backing here

Line: Weight-forward floating line. Consider a long-leader-specific taper for delicate presentations.

Leaders:

• Nymphing: 9' 4X tapered, add tippet sections as needed
• Dry fly: 12-15' 5X or 6X tapered, with fluorocarbon tippet for nymphs, mono for dries

Essential Accessories:

• Magnifying threader (you'll need it for size 24+ flies)
• Small strike indicators (yarn, small bobbers)
• Hemostats for barbless hook removal
• Rubber mesh net
• Polarized sunglasses - essential for sight fishing in clear water

Regulations

The Quality Waters (first 3.75 miles below the dam) have specific rules:

• Catch and release only - all trout must be returned immediately
• Artificial flies only - single, barbless hook
• Maximum 2 flies per line
• Valid New Mexico fishing license required

Below the Special Trout Waters, regulations shift to statewide rules with bag limits. Check New Mexico Game and Fish for current regulations.

Access & Logistics

Getting There

The San Juan is in the northwest corner of New Mexico, about 44 miles east of Farmington. From Albuquerque, it's roughly 3 hours. From Denver, about 5 hours via Durango.

Nearest towns:

• Navajo Dam (closest, limited services)
• Aztec (15 miles, more amenities)
• Farmington (30 miles, full services)

Parking Areas

Three main access points within Quality Waters:

• Upper River: 4.4 miles from Hwy 173/511 intersection
• Texas Hole: 3.8 miles from intersection
• Lower Flats: 2.7 miles from intersection

Parking can fill early on weekends. Arrive before sunrise for Texas Hole access.

Lodging & Fly Shops

On the Water:

• Fisheads of the San Juan - Lodge, guide service, fly shop
• Soaring Eagle Lodge - Lodge and guide service since 1991
• Abe's Motel & Fly Shop - The original San Juan outfitter

Guides:

• About Trout - San Juan specialists
• Float 'N Fish - Walk/wade and float trips
• San Juan Fly Fishing - Full-service guide operation

A guided day runs $400-500 and is worth it for first-timers. The guides know exactly what's working and can cut your learning curve dramatically.

Common Mistakes

1. Fishing too heavy: Light tippet (6X-7X) and small indicators are essential
2. Ignoring fly cleanliness: Algae on your fly kills the drift - check constantly
3. Casting too far: Most fish are closer than you think
4. Wrong depth: If you're not occasionally ticking bottom, you're too high
5. Arriving late: Texas Hole fills up by 8am on weekends
6. Underestimating the cold: Even in summer, that 42°F water chills you fast

Using RiverReports

Before your trip, check:

• San Juan River flows near Archuleta for real-time CFS
• Historical flow comparisons to understand current conditions
• Weather forecasts - overcast days bring better dry fly action

The San Juan's tailwater nature means stable, predictable flows. Unlike freestone rivers, you won't wake up to blown-out conditions. But checking flows helps you understand fish positioning and wading access.

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Quick Reference: What to Bring

Item	Size/Type	Notes
Midges	#20-28	Zebra, RS2, black larva
BWOs	#20-24	Parachute Adams, Sparkle Dun
San Juan Worms	#14-18	Red, tan, brown
Tippet	5X-7X fluorocarbon	Lots of it
Leader	9-12' 4X-5X	Long and fine
Strike indicators	Small	Yarn or micro bobbers

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