Time: 11:00AM – 4:30PM
Location: Below Gross Reservoir
Readers cannot see me, but I am still smiling from my day on South Boulder Creek. Today was a strong affirmation of the value of these blog posts, so let me explain.
I noticed last week that Denver Water finally lowered the releases from Gross Dam to 144 CFS, so I committed to making the trip in the near term. Today, Tuesday August 8 was that day. Knowing that South Boulder Creek was my destination prompted me to search my blog for all the log reports that detailed my fishing trips to the small tailwater northwest of Golden. The common thread on nearly all the August visits was green drakes. Green drakes hatch in the freestone rivers and streams in Colorado from the middle of July until the end of July, but their emergence seems to be delayed in tailwaters such as the Frying Pan River and South Boulder Creek. I suspect this circumstance is related to the cold bottom releases from the upstream dams.
Before I departed on Tuesday morning I checked my fly box and reviewed my selection of green drake imitations. I carry three styles, and I never know which one will fool the wild trout. I counted my comparaduns ribbed and not ribbed, parachute green drakes and Harrop hair wing green drakes; and I concluded that I possessed adequate quantities of each. With this inventory task completed I set out on the short drive to the parking lot above the stream near the outflow from the dam. I followed the directions on my map application on my iPhone, and this route reduced my driving time to 58 minutes. I generally allotted 75 minutes for my previous route that tracked on I70, CO 58, and CO 93.
Needless to say I anxiously anticipated my day on South Boulder Creek; however, my spirits sank a bit when I pulled into the parking lot and realized I would have significant company on Tuesday, a weekday no less. Eight vehicles were parked in the small lot, and I snagged a spot on the northern edge, a rarity for me on a weekday. As I pulled on my waders and strung my Loomis five weight rod, the fishermen on either side of me met with another angler who appeared to be the leader of the threesome. The head guy was alarmed by the number of cars in the lot, and he proposed that they move and “fish the inlet”. I could only assume that he was proposing a drive to the Gross Reservoir parking area accompanied by a one mile hike to the inlet where South Boulder Creek enters the reservoir. The two followers agreed, although it seemed to me they were reluctant to do so. That eliminated two cars, and now I had six remaining vehicles to be concerned about.
I proceeded with my preparation and decided that I would hike as far as the higher flows would allow in order to escape the unexpected crowd of fishermen. The air temperature was in the upper fifties, and the sky was mostly clear, as I began my descent of the steep trail to the creek. A large yellow sign at the top of the trailhead notified of bridge construction and warned to expect delays. I thought this was odd, as the only bridges were two pedestrian spans over South Boulder Creek.
When I reached the edge of the creek, I was pleased to learn that 144 cfs (I later learned when I returned home that the flows were actually reduced to 90 cfs on Tuesday morning) was very manageable for wading, and my expectations surged a bit. I crossed the stream below the small island near the beginning, and as I forded the wide relatively shallow area, I spotted a truck on the lane on the other side. I generally climb on to the bank in the area posted as private, but because of the activity, I waded along the edge until I reached the gate that signifies public access. I glanced back at the truck, and it was backing down the lane, and I assumed that it was transporting materials to be used in the bridge repair. This raised my concern that I should not have crossed, since I now needed to cross the pedestrian bridge to reach the downstream areas that I targeted for my day of fishing.
Fortunately when I approached the bridge, it was apparent that the work had not yet begun, and I breathed a sigh of relief, as I was on my way to farther penetration of the Walker Loop. I passed three solo fishermen on the upper water, so that accounted for three of the cars in the parking lot. Another fisherman waded into the creek in the boulder section downstream from the bridge, and eventually I ran into a man and woman together not far below the place where the fisherman path diverges from the Walker Loop trail. As near as I could tell, these were the last anglers that originated from the parking lot.
When I created a decent distance from the last anglers encountered, I cut down to the water and began my day with a tan pool toy, beadhead hares ear nymph, and salvation nymph. The water before me was exceptional with an abundance of pockets and runs of moderate depth. I managed to land a couple small brown trout on the salvation nymph, but I was not satisfied with the start of my fishing day. Aside from the landed fish, the pool toy hopper attracted significant attention in the form of refusals, and this distracted from the subsurface offerings.
I decided to rectify the situation, and I moved to a size 14 medium olive stimulator. Initially this enticed a couple of small brown trout as well, but then it became an object to be inspected but not eaten. The fish count stood at four, albeit small fish, when I spotted two green drakes, as they fluttered skyward from the stream. The combination of this observation and my review of the blog posts, which documented green drake success in August, convinced me to attach a Harrop hair wing to my line.
Once again the change initiated some initial success, as two trout slashed the bushy mayfly imitation, but then the refusal cycle reappeared. In hindsight I believe that the fish that chose to eat, were in faster riffles; whereas, those that rejected the fly occupied slow moving pools. I was convinced that the green drakes were favored by the South Boulder Creek trout, but the Harrop version did not meet their specifications. I scanned the green drake section of my fly box and plucked a size 14 comparadun with no rib. This fly was effective on the Cache la Poudre River in July, so I tied it to my line and took a deep breath. The comparadun presented a more slender profile, and several fish liked the lean look allowing me to build the fish count to ten. However, fish that ate the large mayfly imitation were fewer than those that refused or elevated to look with no follow through. In addition to the irregular performance of the the fly, it became saturated with water, and even my best efforts to dry it were increasingly futile.
I decided to sit on a log to eat my lunch. I pondered my next move, while I observed the quality deep pool and run next to my dining area. I landed ten fish in my first hour, and yet I was dissatisfied with the production of my fly choices. How could this be? An experienced fly fisherman would know the feeling of fishing through high quality water that assuredly contains decent fish, yet somehow coming up empty, or the takes are accompanied by an overabundance of refusals and brief hook ups. That sentence accurately described my state of mind.
I remembered the blog entries, that I read the night before, and I recalled the documented success of the parachute green drake imitations that eventually unraveled. After lunch I followed through on my recollection and replaced the comparadun style with a size 14 parachute green drake. This version contained a white wing post that enhanced visibility and a maroon thread rib on the abdomen. I tested the fresh dry fly in the deep pool, and after a small fish rejected it in the fast center section, I lobbed it to the shelf pool on the far side. Success! A decent brown trout streaked to the surface and crushed the fake. Similar success greeted my fly changes earlier in the day, so I resisted a celebration.
The celebratory restraint was unnecessary. I moved upstream, and over the next 2.5 hours I experienced some exceptional dry fly fishing. The fish counter clicked frequently and moved from ten to thirty-six, and all the fish were fooled by the parachute green drake. In fact two flies produced all the fish, and the first one accounted for 75%. During this time I noticed additional naturals, but the hatch was not obvious, and I spotted very few rising trout. Western green drake hatches are notoriously sparse, but the size of the meal makes up for the reduced quantity of insects. The trout were definitely tuned into green drakes.
It did not seem to matter what type of water I cast to. Riffles were absolute producers, and the seams of deep runs were also worth exploring. I was stunned to see several fish flash downstream for several feet to intercept the large dry fly before it tumbled over the lip of the pocket. In one case a brown trout bumped the fly twice and then finally grabbed it before it escaped. At the point where it inhaled the drake, it was five feet downstream from its initial inspection. That is due diligence although not very effective, if the goal is to avoid getting hooked in the mouth. Four or five times I lost sight of the fly, as it got tugged under by the currents, so I lifted and felt the weight of a fish. These subsurface takes resulted in some of the larger trout on the day, and it seemed like the rainbows were more likely to nab drowned green drakes than brown trout.
By 2:30 some dark clouds appeared overhead accompanied by the sound of distant thunder. I pulled on my raincoat during lunch for added warmth, so I was prepared for precipitation, and I continued fishing as light rain commenced. Suddenly a flash of light brightened the sky, and a clap of thunder followed shortly thereafter. This meant the lightning was close by, so I quickly climbed some rocks and found a refuge next to a tall rock wall that leaned toward the north and provided a slice of protection from the rain. I waited impatiently for fifteen minutes until three o’clock, and then the sky brightened in the west, and the sounds of thunder faded.
I returned to the creek and resumed casting the parachute green drake, but my second imitation also became waterlogged, and the fish were not responsive. The rain eventually stopped, and the sun emerged briefly, and this stimulated a wave of insect activity. I observed a couple green drakes, but an abundance of smaller mayflies now took center stage. I continued prospecting with the waterlogged parachute green drake and added a few more fish, but I began to wonder if perhaps this was a time when trout might favor the active nymph stage of the pale morning dun. I quickly converted to a two fly dry/dropper with a yellow fat Albert on top and a salvation nymph as the dropper. The theory was not correct. The fish ignored this approach, so after twenty minutes of flailing the water with no reward for my efforts, I reverted to a green drake.
During my 2016 green drake interaction, I used the comparadun with success after the parachute versions unraveled, so I gave this ploy another try. It did not pan out, and my watch indicated that it was 4PM, so I decided to begin the long forty minute hike back to the parking lot. As I was trudging along on the trail, I stopped at several favorite pools to make some last ditch casts. At the first prime pool I encountered, I noticed a few rises along the right side. I floated the green drake comparadun in the vicinity, but this merely encouraged an inspection. I suspected that pale morning duns were prevalent, so I converted to a size 16 light gray comparadun. The third drift of the slender PMD imitation prompted a subtle take, and I hooked and landed a pretty ten inch rainbow.
I turned my attention to the shelf pool on the other side of the strong center current. A small fish showed itself with several splashy rises at the tail, but some downstream drifts failed to entice another rise to my fly. It was at this time that a swarm of mayfly spinners hovered over the pool and the area I was casting to. They did not appear to be touching the water, but several fish rose while this mating event developed. Maybe some strays touched down ahead of the main orgy? I replaced the light gray comparadun with a cinnamon version and mashed down the deer hair wing so that some deer hair spread to the side of the thorax. This was my attempt to match a pale morning dun spinner, but it did not succeed. While executing casts in this same pool, I spotted another pair of green drakes. Perhaps I abandoned the big boy too soon? I tied the green drake comparadun back on my line, but they shunned it as well, and I surrendered to the pool and moved on.
My last stop was the long deep pool between the pedestrian bridge (which now displayed signs on both ends warning of delays) and the path that ascends to the parking lot. I was shocked to see this perpetually occupied location vacant, so I stopped to make a few exploratory casts. I once again knotted the size 16 light gray comparadun to my line, and it rewarded me with two rainbow trout in the ten and eleven inch size range. I ended my day with three rainbow trout that sipped the comparadun to reach thirty-nine fish.
What a wonderful day on South Boulder Creek! All but the first two fish ate dry flies, and the action on the parachute green drake was superb. Tuesday was a testament to my commitment to my blog and to tying my own flies. In all likelihood had I not read about my success with green drakes on August 4, 2016, I would not have converted to the parachute green drake. Tying my own flies allowed me to capitalize on my experience and many prior interactions with green drake hatches to produce three different styles, and the parachute version became the favorite on Tuesday. I foresee a return trip to South Boulder Creek in my near future. In fact after chronicling my day, I am ready to return right now.
Fish Landed: 39