The rising sun looked like a red disk in the rear view mirror. It would be another smoky morning on the Front Range, but I was headed west toward the South Platte River for what I hoped would be less smoke and a hatch of small mayflies know as “tricos” to fly fishers.
Trico is a shortened version of Tricorythodes, the genus name that entomologists assigned to a diminutive mayfly with a black body and grayish white wings when it emerges from its nymphal shuck on the water’s surface. The wings quickly harden and after a second molt become clear when the females, which hatch first thing in the morning, take off into the air to meet up with males that hatched the previous evening. Together they form cloud-like mating swarms over the water.
For me, the mating swarms are one of the natural wonders of the world where tens of thousands of tricos mate after which the females descend to the river, oviposit their fertilized eggs and fall dead, or “spent” as fly fishers say, on the water. The males quickly follow suit ending up spent on the water’s surface, too.
Needless to say, the trout feed voraciously on the hatch of females in the morning and then on the spent males and females. The rub for fly anglers is there are so many tricos on the water that it can be difficult to get a trout to take your trico imitation.
The tricos typically account for much of my midsummer angling, but this year other matters had intervened. This was my first trip to the South Platte River in Elevenmile Canyon to fish to the hatch and spinner fall. The rule among trico anglers is get to the water early, fish the hatch of females and then fish the spinner fall. By early I mean before the sun hits the river.
Fishing the trico event is never quite the same. Sometimes, you catch fish first off when the females hatch. Other days you can’t buy a strike during the hatch, but do well when the trout switch to feeding on the spent spinners. On the best of days, you do well during both the hatch and spinner fall.
For me the hatch is often difficult, but I can usually catch trout during the first part of the spinner fall. Fooling the trout gets more and more difficult as the spinner fall progresses. I carry a bunch of fly imitations that differ slightly and work my way through them until I find one that appeals to the trout.
Most of the time I fish a two-fly rig that includes an easy to see dry fly trico imitation with a more difficult to see spent spinner or emerging trico imitation trailed a foot or so behind it. The dry fly helps me locate about where the trailer fly is and sometimes acts as a strike detector when a trout takes it.
I arrived at Elevenmile Canyon plenty early. My first surprise was there weren’t many campers in the campgrounds along the river. I expected them to be full. The second surprise was there were no cars heading upstream to the catch and release area.
It was eerie when I got to the parking area near the section of river I like to fish and no one was there. I figured I’d see them later. I took my time rigging up and then headed out. I still hadn’t seen any other anglers.
After I crossed the river, I took a few minutes to watch the water. The fish weren’t rising yet, so I tied on a size 14 Elk Hair Caddisfly and trailed it with a size 22 Zebra Midge. The caddisfly imitated the large moth-like insects that are often fluttering over the water first thing in the morning. There are times when the trout are crazy for them. The zebra midge serves as a general purpose imitation of the trico nymph.
The zebra midge produced one nice rainbow trout before the hatch of female tricos began. I switched over to a size 20 Hackle Stacker dry fly trailed by a size 22 wingless trico spinner. It’s just a black thread body trico spent spinner imitation tied without the wings. Pennsylvania angler Rod Rohrbach clued me in to the pattern a number of years ago. I think it imitates a trico nymph on the water’s surface before its wings unfold.
This is an extremely vulnerable stage for the emerging trico adult and sometimes the trout go nuts on the imitation. That was the case this morning. From my first cast on, it was rock and roll. I never changed flies even when the trout switched over to eating the spent spinners because they were still mad for the wingless spent spinner imitation.
Eventually, I looked up and realized there still weren’t any other anglers in sight. This is so unusual that it spooked me. I thought maybe the river was under some sort of no fishing regulations because of overly warm water temperatures. Warm water is a real concern this year, and several Colorado rivers do have voluntary no fishing advisories during the afternoon hours. I took a water temperature reading just to be on the safe side. It was a healthy 57 degrees.
So, all was well. Just me, the tricos, the trout and the river for the entire morning. Figure that.