Tucked away in the southern reaches of the San Juan Mountains, the Conejos River winds through some of the most beautiful and remote landscapes in Colorado. As the days of summer give way to the crisp mornings of fall, September offers a prime window for fly fishing enthusiasts to experience the Conejos River at its best. The combination of fewer crowds, cooler weather, and active trout feeding before the colder months creates an ideal setting for a memorable fly fishing adventure.

In this guide, we’ll cover everything you need to know about Conejos River Colorado fly fishing in September, including the best lures, tackle, waders, clothing, trout species, water types, and nearby towns to base your trip.

The Magic of September on the Conejos River

September brings a noticeable shift to the Conejos River. The aspen trees begin to change color, casting a golden hue along the riverbanks. Temperatures cool off, with daytime highs in the 60s and 70s and chilly nights dipping into the 40s. This change in weather stirs the river’s trout, pushing them to feed aggressively before the winter months.

By September, the summer snowmelt has long subsided, leaving the river at its ideal flow rate for wading and fishing. The river’s waters run clear and cold, making it easier to spot trout as they move from their summer haunts into prime feeding zones.

Trout Species of the Conejos River

The Conejos River is known for its healthy population of trout, offering a mix of species for anglers. While brown trout dominate the river, you’ll also encounter rainbow trout, and cutthroat trout. In the higher elevations of the river’s headwaters, you may even come across the elusive Rio Grande cutthroat, a native species with vibrant colors and strong fighting spirit.

Here’s a quick rundown of the trout species you can expect to target:

  • Brown Trout: Known for their wary nature and aggressive strikes, brown trout are the most common species in the Conejos River. They thrive in the river’s deeper pools and along undercut banks.

  • Rainbow Trout: These feisty fish are known for their acrobatics and strong runs. Rainbows can be found in the faster riffles and runs of the river, particularly during cooler months.

  • Cutthroat Trout: The native Rio Grande cutthroat is a prized catch for fly fishers on the Conejos River, often found in the higher elevations. With their striking red throats and vibrant hues, these trout are a true testament to Colorado’s wild beauty.

Best Fly Patterns and Lures for September

September is an interesting month for fly fishing because trout are still eager to take summer flies but are also becoming more interested in late-season patterns. Here are some fly patterns that are effective on the Conejos River during September:

  • Terrestrials: Grasshoppers, ants, and beetles are still productive in early September, especially in the warmer afternoons. The banks of the Conejos are often lined with grassy meadows, providing plenty of terrestrial insects that fall into the water.

    • Recommended Patterns: Chubby Chernobyl, Hopper, Parachute Ant, and Beetles

  • Mayflies: As the days cool, Blue-Winged Olive (BWO) hatches become more frequent. These small mayflies tend to hatch on overcast days or in the mornings and evenings.

    • Recommended Patterns: BWO Duns, Parachute Adams, RS2

  • Caddis: September still sees plenty of caddis activity. You’ll find these bugs in the late afternoons, particularly in riffles and faster-moving water.

    • Recommended Patterns: Elk Hair Caddis, X-Caddis, and Sparkle Pupa

  • Nymphs: As the temperatures drop, trout will move deeper, feeding subsurface on a variety of nymphs and emergers. Nymphing can be particularly effective in the deeper pools and slower runs.

    • Recommended Patterns: Pheasant Tail Nymph, Copper John, Zebra Midge, and Hare’s Ear

Don’t forget to carry a few streamers, especially for brown trout. As the spawning season for browns approaches in late September, they become more territorial and aggressive, making streamers like Woolly Buggers and Zonkers especially effective.

Tackle and Gear

When fishing the Conejos River in September, you’ll need a versatile setup that can handle a range of water types, from fast riffles to deep pools. Here’s a breakdown of recommended tackle and gear:

  • Rod: A 9-foot 5-weight fly rod is perfect for most conditions on the Conejos River. It’s light enough for delicate presentations but still has enough backbone to handle larger trout, especially browns. For those targeting smaller trout in the headwaters, a 4-weight rod can be a fun option.

  • Reel: A quality reel with a smooth drag system is essential, especially when fishing for aggressive brown trout. While trout on the Conejos don’t typically make long runs, a reliable drag will help when you hook into larger fish in fast current.

  • Line: A weight-forward floating line works well for most fly fishing situations on the Conejos. For nymphing or fishing streamers, you might consider adding a sink-tip line or using weighted flies to get your flies deeper.

  • Leaders and Tippet: In the clearer water of September, use 9-foot leaders tapered down to 4X or 5X tippet for dry flies and nymphs. For streamers, you can get away with a shorter leader and 3X tippet.

Waders and Clothing

September on the Conejos River can be unpredictable in terms of weather. Mornings can be cold, with frost covering the meadows, while afternoons might warm up enough to fish in just a light shirt. Here’s a guide to waders and clothing for a September trip:

  • Waders: A good pair of breathable chest waders is a must for the Conejos. The river’s water stays cold year-round, and even in warmer weather, you’ll want protection when wading deeper sections. Paired with wading boots that have good grip (felt or rubber with studs), you’ll be ready to fish comfortably all day.

  • Layers: Dress in layers to handle the temperature fluctuations. Start with a moisture-wicking base layer, followed by an insulating fleece or wool layer for warmth. Top it off with a waterproof, windproof jacket in case of afternoon showers or wind.

  • Hat and Gloves: A wide-brim hat or cap will protect you from the sun, while fingerless gloves can be useful for cold mornings and evenings, especially when handling gear.

Most Productive Water Types

The Conejos River offers diverse water types that cater to different fly fishing techniques. Here are the most productive areas to target:

  • Riffles and Runs: The faster-moving sections of the river provide plenty of oxygen and food for trout. Look for trout holding just behind rocks or in the seams where fast and slow water meet.

  • Pools: Deeper pools, often found downstream of riffles or bends in the river, are prime spots for trout to hold and feed. These pools are especially productive in the cooler parts of the day.

  • Undercut Banks: Brown trout, in particular, love hiding undercut banks, using them as cover while waiting to ambush prey. A well-placed terrestrial fly or streamer can draw aggressive strikes.

  • Pocket Water: In areas where large rocks break up the current, you’ll find pockets of calmer water where trout sit and wait for food to drift by.

Towns Near the Conejos River

The Conejos River flows through a remote part of Colorado, but there are a few nearby towns where you can base your fly fishing trip:

  • Antonito: The closest town to the Conejos River, Antonito is a small, rural community that offers access to the lower sections of the river. It’s a great base for exploring the river’s waters while enjoying the quiet, laid-back atmosphere of southern Colorado.

  • Platoro: Nestled near the headwaters of the Conejos River, Platoro is a tiny, high-altitude town that offers close access to the river’s upper reaches. It’s a perfect spot for anglers looking to fish for Rio Grande cutthroat trout.

  • Alamosa: A bit further away, Alamosa is a larger town that offers more amenities and services. While it’s about an hour’s drive from the Conejos River, it’s a good option if you’re looking for more dining and lodging choices.

Conclusion

Fly fishing the Conejos River in September is a magical experience that combines breathtaking scenery, solitude, and the chance to catch beautiful wild trout. With the right gear, fly patterns, and knowledge of the river’s water types, you’ll be well-prepared for a successful day on the water.

So pack your gear, dress in layers, and head to the Conejos River this fall for some of the best fly fishing Colorado has to offer. Whether you’re after the aggressive browns, colorful rainbows, or elusive cutthroat, the Conejos River promises a fly fishing adventure you’ll never forget.