Time: 10:30AM – 3:00PM
Location: Boulder Canyon
After a couple days of cool weather and appointments I was anxious to return to my beloved pastime of fly fishing. The weather forecast for Thursday was promising, so I prepared for a trip to Boulder Creek in the canyon west of Boulder, CO. Originally I hoped to visit the Big Thompson River, but a review of flows on the DWR web site indicated an increase and some erratic movement on the chart, so I decided to avoid for a few days until things settled down.
I arrived at a pullout along Boulder Creek at 10AM on Thursday morning, and the weather forecast proved to be accurate, as the temperature climbed into the sixties and the sky was deep blue during my entire stay. The flows were at 52 cfs as advertised on the web site, and clarity was superb. Favorable conditions awaited my entry into Boulder Creek on May 4.
I began my day with a size 8 Chernobyl ant, emerald caddis pupa and beadhead hares ear, as this combination performed well for me on the North Fork of the St. Vrain Creek on Monday. During the early going the nymphs were ignored, and the Chernobyl ant attracted mostly refusals with the exception of one small brown, that smashed the over sized foam ant imitation.
After a half hour of refusals and one landed fish, I experimented with a gray stimulator in an effort to downsize, but the change failed to elicit any reaction from the Boulder Creek trout. I pondered my next move and considered the fact that the fish were rising to the large Chernobyl but not eating. I deduced that they were looking for a smaller terrestrial, so I switched to a size 12 Jake’s gulp beetle.
Voila! This produced, and I landed two additional small trout that gulped the beetle with confidence, before I stopped to eat lunch. After lunch another beetle chomper incremented the fish count by one, and then I spotted occasional blue winged olives hovering above the stream. This observation prodded me to switch back to a dry/dropper arrangement with a smaller size 10 Chernobyl ant, beadhead hares ear, and RS2.
The fish counter moved from four to ten over the remainder of the afternoon, with one fish taking the RS2, and one nabbing the hares ear. Surprisingly the remainder of the afternoon catch crushed the Chernobyl. Several brown trout feeders in the early afternoon moved at least a foot downstream to catch up to the drifting foam terrestrial. I recognized this as a sure sign of an effective fly.
At 2:30 I was frustrated by the increasing rate of refusals to the foam ant, so I reverted to Jake’s gulp beetle and ended the day with an eight inch brook trout. I probably should have switched to the beetle earlier, but it is always easy to look back. On Thursday I landed eleven fish, and all were browns except for the final brook trout, The largest fish was only ten inches, but it was a gorgeous spring day with the leaves beginning to break out on the trees in Boulder Canyon.
Fish Landed: 11