Time: 11:30AM – 3:00PM
Location: Below Buttonrock Dam
North Fork of the St. Vrain 10/13/2017 Photo Album
Steady flows of 26 CFS attracted me to the North Fork of the St. Vrain Creek below Buttonrock Reservoir. That and a trip to the Big Thompson on Thursday during which I traveled along the North Fork for several miles.
I found myself in the parking lot below the gate that marks the entrance to the access road to the St. Vrain at 10:45AM, and after donning my waders and assembling my Orvis Access four weight I was on my way. I hiked for thirty minutes and then angled to the stream where the bank was comfortably gradual. The temperature at the parking lot was fifty degrees and the wind gusted with surprising frequency. These factors caused me to wear my fleece and raincoat as well as my New Zealand billed hat with ear flaps. The thirty minute hike caused me to overheat a bit, but I embraced the double layers throughout the day and never felt over dressed.
Prime Trout Water
The stream meanwhile was quite clear, and the flows were nearly ideal. On Thursday I experienced success with a gray size 14 stimulator, so I elected to begin Friday with the same offering. The Big Thompson and St. Vrain are both front range streams on the eastern side of the continental divide, so perhaps the fish savored the same food items? The choice proved to be favorable, as I landed two brown trout in the first hour, and I managed to connect temporarily with a third, before it leaped above the creek and slipped free of the hook. The section where I began was mostly in shadows, and I discovered that a downstream drift provided the best visibility. All three of the fish in the first hour emerged from deep narrow slots where several currents merged, and over the remainder of the day I discovered that these were the most productive stream structures.
Typical Small St. Vrain Brown Trout
After lunch the catch rate slowed a bit, but I continued with the stimulator, and upon spying some blue winged olives, I added a size 20 RS2. The stimulator produced a fourth small brown trout, and then the RS2 earned its keep, when a small brown trout nabbed the baetis nymph, as it began to swing in a relatively shallow area. I pressed on with the abbreviated dry/dropper approach, but the BWO hatch intensified, and it seemed that my small nymph should be attracting more attention. I concluded that I needed to get deeper by pairing the baetis nymph with a larger subsurface pattern.
I opted for a yellow fat Albert, and below it I attached a beadhead hares ear and a beadhead soft hackle emerger size 20. The foam top fly suspended the two nymphs, and the weight of the larger hares ear produced deeper drifts. The change succeeded somewhat, and I landed two additional small brown trout to increment the fish count to seven. The two fish that succumbed to the dry/dropper snatched the soft hackle emerger at the tail of the dirft.
A Bit Larger
By 2:30 I reached the point where a lower outflow from the dam merged with the main creek that emanated from the main spillway upstream. The confluence created several nice deep runs and a wide smooth bordering pools. I began drifting the dry/dropper offering through the lower run, but my casts were futile. I crossed the lower branch and positioned myself between the two merging currents and paused to scan the setting. Quite a few tiny blue winged olives danced over the surface, and a series of rises commenced along the main runs. Many of the splashy rises appeared to result from tiny fish, but I spotted a larger feeder that hovered a foot below the surface downstream from my position. I decided to convert to a CDC BWO for the last thirty minutes of fishing.
I opened my fly box and extracted a size 24 CDC olive and knotted it to my line, and then I lobbed a downstream cast to the area of the sighted fish. On each cast I checked my cast abruptly at eleven o’clock, and this created a pile of slack line that allowed the small morsel to gently drift downstream. The third attempt was perfect, and as the tuft of CDC floated into the vicinity of the target fish, it darted to the left and grabbed the fraud. I quickly powered the eight inch brown trout into my net, but despite the small size it was a thrill to fool a trout with a tiny fly and a downstream drift. It took a while to dry the CDC wing, but eventually I was back in action, and I landed two additional six inch rainbow trout to complete my day with a fish count of ten. I suspect that the small rainbows resulted from a stocking of subcatchable rainbows in an effort to supplement the natural reproduction of the brown trout subsequent to the 2013 flood.
Deep Coloration
The largest fish from the St. Vrain on Friday was a ten inch brown, but I did manage to reach double digits, and seven of the landed fish consumed a dry fly. The weather was a bit chilly, but the scenery was spectacular, and I had the stream to myself. I am sensing that twenty fish days are history, so I was quite pleased to enjoy reasonable success on Friday the 13th.
Fish Landed: 10