The Blue River below the Dillon Dam can be a fickle beast, but is highly regarded for its beefy mysis shrimp eating bows, year-round fishing and its ease of access. While it can be even more challenging this time of year, the winter is one of our favorite seasons to hit the water. In the warmer months, the Troutlets (aptly named for its proximity to the Silverthorne outlets), sees a tremendous amount of angler pressure resulting in ultra picky trout and in some cases a frustrating time on the water. The winter months can be equally frustrating, but if you can manage to weather the cold, you’re bound to have a good time. We’ve found that the Blue is an ideal location for teaching anglers how to properly fish the winter months and we’re excited to announce we will be doing another round of winter fly fishing clinics this year! We booked up fast so stay tuned for more clinics and fish alongs this year. In the meantime, we wanted to give you an update on how the Blue is fishing and talk through our approach and thought process when fishing this tricky tailwater.

Outing at the Troutlets

The other weekend we hit the Blue and managed to have a productive day on the water, despite freezing our asses off. Overcast skies played to our advantage, giving trout a sense of protection and gin clear water made for easy sight fishing.

  • FlyCast Explained: In the winter, trout on the Blue tend to find a comfortable holding place (depending on the time of day and air/water temperature) and stay put. As such, sight fishing is one of the key factors between a slow and very productive day.

The morning was cold! Despite our constant advice to sleep in and let it warm up, we were eager to beat the ski traffic. In an attempt to blow some time, we stopped at our favorite breakfast spot, Blue Moon Bakery, as well as the local fly shop in Silverthorne, The Colorado Angler. The guys at The Colorado Angler are always friendly and more than willing to give you honest and unbiased intel. By the time we parked near the river, it was 8:30 am and after staring at the car thermometer for about 30 minutes, waiting for even a 5 degree improvement in air temperatures, we had no such luck and succumbed to the river’s call. It was a bone chilling 7 degrees by the time we made our first cast, but it felt like -10 degrees given moisture in the air. Air pressure was on the downswing and slightly below productive levels.

  • FlyCast Explained: Given low air pressure, we recommend leading your nymph rigs with a slightly bigger fly followed by one or more smaller neutral colored midge patterns. With moisture in the air, you will want to be conscious of hatch activity. However, air temps need to be higher.

Knowing this we started with a San Juan Worm followed by a size #22 black Zebra Midge. We walked with caution as we approached the water and begun by hitting the outer seams closer to the bank.

  • FlyCast Explained: In the early hours, when air and water temps are cold, trout tend to hold in the slack water close to the banks. This water is slightly warmer and allows them to expend less energy.

Troutlets #2

After several casts and seriously considering the risk of frostbite, we hooked into our first trout! It came as a bit of a surprise as we were distracted by frozen guides, line and fingers. Nonetheless, a little brown took our Zebra Midge. Once we recovered from the cold shock of releasing the trout back into the water our confidence was on the upswing.

As the day went on and air/water temperatures rose, we switched up flies. Given no luck on the San Juan Worm, we swapped it out for a size #10 black Pat’s Rubber Legs followed by a black Foamback RS2 and decreased the amount of split shot so as to reach the mid to upper water columns.

  • FlyCast Explained: The thought being, air pressure was still low so we kept with a bigger lead fly. However, with rising air/water temps we anticipated some hatch activity. Hence the emerger pattern.

At this point, air temps had reached 20 degrees and we had moved past the slack water and were focusing on the slower runs closer to the center of the river. After a few casts it was game on as trout were more willing to move for our flies.

Troutlets #3

We called it quits at about 1 pm, but could have easily gotten another three hours of productive time on the water. The morning was fairly slow and cold, but given a little patience and persistence, we managed to have an awesome time! Our approach changed by the hour and we took full advantage of pristine water clarity. We didn’t see much in the way of surface action, given sub-freezing air temps, but it is not uncommon to see sporadic midge hatches in the late morning and early afternoon. While the cold undoubtedly tested our tolerance for pain and our sanity, it was well worth our time.

At FlyCast, it is our mission to help you have the most productive day on the water as possible. So if you have any questions or need fly fishing advice, don’t hesitate to reach out! Otherwise, check out our daily and weekly reports and forecasts at