Time: 11:15AM – 3:00PM

Location: Below Gross Reservoir

South Boulder Creek 10/196/2026 Photo Album

I had my eye on South Boulder Creek for two months, while the water managers released flows from the dam at a ridiculously low 4 CFS. Finally I saw a post on Instagram from one of the Boulder fly shops showing that the flows were increased to 66 CFS. I opened the DWR web site and confirmed that flows were at a steady 66 CFS for the last three days, so I made plans for a day of fly fishing on Monday, October 19, 2026.

Lovely Pool

Leaving the house at 8:30AM enabled me to drive to the parking lot, gear up, and hike to my chosen starting spot by 11:15AM. The temperature in the parking lot was 51 degrees. I knew I would perspire on my inbound hike, so I stuffed my long sleeve Columbia undershirt in my backpack along with my lunch and raincoat, and I tied my fleece hoodie around my waist under my waders. I rigged my Loomis two piece five weight for a sturdy, slow action dry fly casting rod.

Another Fine Rainbow Trout

When I arrived streamside, I shed all my layers and swapped my damp short sleeve undershirt for the Columbia version, and then I layered on my fishing shirt and my raincoat. I never resorted to the fleece hoodie, but I was pleased to have the safety net of another layer.

Left Side Pool

To begin my quest for trout I configured my floating line with an amber ice dub chubby Chernobyl and a 20 incher. These flies remained on my line for thirty minutes, until noon, when I paused for lunch. The 20 incher accounted for a small brown trout, but the chubby Chernobyl was attracting refusals. Given the interest in my surface offering, I opted to go with a double dry in the form of a peacock hippie stomper and a size 16 light gray deer hair caddis.

Ooh. Nice Brown Trout

The hippie stomper followed in the footsteps of the chubby Chernobyl, as I enticed looks and short strikes but no eats. The caddis also coaxed a splashy refusal. The morning was sending out ominous vibes, as I sat on a large rock to consume my lunch and ponder my next move.

Bank Side Pool

I landed one trout on a nymph, but all the other action was initiated by dry flies. I concluded that the trout were primarily looking toward the surface. However, as I observed the stream, I noted a few tiny mayflies, as they floated skyward. In order to cover my bases, I knotted a size 12 Jake’s gulp beetle to my line and followed it with a sunken black ant. For dessert in response to the sparse blue wing olives, I added a  third fly in the form of a size 20 sparkle wing RS2.

The Eye Broke Off from the Shank. A First for Me.

These flies allowed me to boost the fish count from one to fourteen by the time I exited the stream at 3:00PM. The beetle induced four trout to snatch it from the surface, while the RS2 tempted four additional fish into grabs. Five additional stream residents could not resist the tumbling sunken ant. Two of the ant eaters were respectable rainbows in the thirteen inch range, and I felt like the ant attracted larger fish than the other offerings. The fish that nipped the RS2 seemed to react to movement in the form of lifts and swings. The beetle eats were impulsive takes soon after the terrestrial splashed down in the creek.

Excellent Brown by SBC Starndards

I was paused on twelve fish, when I exited the creek and climbed the steep rocky bank to the path. I hiked back toward the parking lot for .5 mile, until I reached my favorite pool. Here I waded in at the tail and landed two additional trout to boost the fish count to fourteen on the day. A fine twelve inch brown trout nabbed the beetle, and a similar sized rainbow was duped by the RS2.

Likely Trout Home

Monday was a fun day on South Boulder Creek. I would characterize the fly fishing as steady. I covered quite a bit of water and endured a large quantity of casts. Unlike other outings on the small tailwater, I often made five or more cast to attractive places, before a fish grabbed my fly. During the warmer months, my chances of hooking a fish decline significantly after three casts, so Monday was different in that regard.

Handsome

I was quite pleased to earn success from my sunk ant. On my return hike I bumped into another angler, and I tried to show him the sunk ant pattern, but when I held it out for his inspection, I realized that it was simply a bare hook with the hackle for legs still attached. Somehow in the process of casting or landing fish, the two bumps got destroyed. I wonder how many more fish I would have caught, had I not been fishing with a bare shank, naked ant?

Secondary Run Was Productive

A fourteen fish day in late October is respectable in my book. The other angler showed me a perdigon that worked well for him, so if I return this season, I might offer an olive perdigon along with the ant. Hopefully the weather holds, and I can bank another day on South Boulder Creek.

Fish Landed: 14