Writing a blog post about a great fly fishing spot almost feels criminal, but having frequented the Blue River for most of my life, I can tell you... the secret is OUT. So, I feel slightly less guilty about writing this article.
As I mentioned, I began fishing the Blue River as a kid and have become intimately familiar with several sections of the river, particularly below Dillon Reservoir. If you've fished these Gold Medal waters before, you've probably seen the massive red slabs swimming upstream below the dam. It truly is a fly fisherman's paradise (aside from being right in the middle of a bustling town). However, these beautiful rainbow trout (and sometimes brown trout) can be quite challenging to catch.
The trout in the Blue River have become seasoned experts at identifying an amateur fly fisherman's offering floating past. During my earlier years of fishing, I would often come up empty-handed in sections below the dam, while my more experienced friends would effortlessly catch five or more fish in the same session.
Though I can't fix your upstream mend through a single blog post, hopefully, you might glean at least one piece of insight that helps you land a trophy on your next trip to fish the Blue River.
1. Sight fishing is overrated on the Blue
Due to the tailwaters of Dillon Reservoir being considered Gold Medal fishing, you'll encounter plenty of other anglers on the river throughout Silverthorne. Consequently, many of the fish you're spotting in the river have already had countless flies tossed their way on the same day. In my opinion, you have a higher probability of success if you target the less obvious fish. Experiment with ripples and faster-moving sections where it might be more challenging to spot any fish. Remember, just because you can't see them doesn't mean they're not present. This principle also applies to the deeper holes.
2. Change your flies continuously, then stop
Because of the volume of anglers that visit Silverthorne, these fish have encountered everything from Mysis shrimp (small orange shrimp) flowing out of the dam to your trusty Rainbow Warrior. An employee at Cutthroat Anglers once advised me, "You better hope you're not using the same fly as the guy in front of you." Thus, it's crucial to frequently switch your flies after working a specific section of the river. This not only ensures you're not mimicking other anglers but also helps you understand which fly patterns and colors are effective that day. Once you observe a particular fly generating interest or even bites, you've found what I call your "fly of the day." Despite common belief, the experts in the fly shop won't always reveal the best fly for the day.
3. Practice stealth
On the Blue, I find practicing stealth to be even more crucial than on other rivers throughout Colorado. This is likely due to a combination of the water's clarity, the wide basin, and the volume of anglers. The trout here appear to spook more easily. While practicing stealthy movement is important on any river, it's especially vital when fishing the Blue below the dam.
4. Small flies yield BIG fish
It seems that larger fish are more inclined to take the smallest flies when you're fishing on the Blue River. Stick to flies above size 16 for any nymphs you're presenting below the surface, even during the summer. You'll need to downsize even further when fishing in the winter. Once again, the ultra-clear water of the Blue often means that smaller flies yield better results. I've discovered that using a larger, eye-catching nymph down to something as small as a size 20+, such as an RS2, can be effective. Don't hesitate to try using eggs in the fall, as I've found success with them here.
5. Leave no trace
Each year, it seems that there are more and more anglers on the Blue River, especially as the town of Silverthorne continues to expand. Recently, it has become common to find trash floating downstream or caught in eddies. If possible, I encourage you to join me in removing some of this waste as you come across it. If each of us leaves the river cleaner than we found it, the Blue River should remain a stable and resilient ecosystem for these trout to thrive for years to come. As a reminder, always ensure you pick up your tippet clippings.
If you have questions about specific areas to fish or need fly recommendations, please reach out via email or on any of our social platforms. See you out there and remember, KEEP EM WET IN THE NET!