The San Juan River in New Mexico is one of the premier tailwaters in the western United States. Water flowing out of Navajo Dam stays at constant 40 degrees all year long which makes for steady insect hatches and great fishing in the fall and throughout the winter. Consequently, we have a great fishery without the crowds during this time of year.
Midges are the predominate food source for the fish on the San Juan River and using the tiny flies that represent them will catch fish all fall and winter. With the cooler temperatures, the mayflies will start their fall hatches which will continue through November and into early December. This is when the fishing can go from good to exceptional.
Midge and mayfly patterns on a standard two fly nymph rig under an indicator is usually the most productive way to fish these hatches but there are times you can have a lot of fun fishing dries to rising fish. The fish on the San Juan can be a bit “leader shy” so often 5x and 6x tippet is a necessity. If you are using a short nymph rig in shallow clear water a good thing to keep in mind is to avoid using brightly colored indicators. Using smaller black, white, olive or tan ones can be much more effective and won’t spook the fish.
Even though you can catch some very nice fish with a standard midge set-up, streamer fishing is an under utilized technique on the “Juan”. Wooly buggers, leeches and large streamer patterns are a great choice. These types of flies, stripped through deeper holes and runs, will often bring the biggest fish in the river to the net. Tying your streamers on with the “Non-Slip Loop Knot” (as detailed in the article below) is a great idea. Note: double hook articulated streamers are not allowed to be used in the Quality Waters section of the San Juan River.
Sometime in December when it gets cold enough at night, the thermocline effect will flip the water in Navajo Reservoir making the river a bit cloudy. Some anglers think that this is marks the end of fishing until the water clears up again; they are 100% wrong! This is when fishing with bright colored eggs, beads and larva on a two fly nymph rig under an indicator really shines. When the water is a bit off-color you can often get away with using 4x tippet; a pleasant change from the required 6x in the clearer water of the summer.
Floating the river in a drift-boat or wading is possible on the San Juan throughout the year however, wading is often is much more productive as you are able to slow down and really work the seams and pockets much more efficiently. As well, when the flows are lower in the fall and winter, you can get to many areas that are not accessible from a drift boat.
Fly fishing on the San Juan can be somewhat “technical” with all the different techniques, fly patterns and water types. It can seem a bit daunting to anglers who haven’t experienced this type of fishing. Going with a friend who is an experienced San Juan angler or using a guide to show you the ropes for your first time or two on this river can pay off in spades.
Article by Scott "Bubba" Smith
Bubba has been a fly fishing guide and commercial fly tier for 40 years and for the last 18 years he has been guiding on the San Juan River. Bubba is now working with us here at Land of Enchantment Guides. Feel free to give him call at our office if you have any questions about fishing on the San Juan River, fly tying or about fly fishing in general.