Cheesman after the Fire
Despite the adversity of whirling disease, the Hayman Fire, and the water demands of three quarters of a million people living downstream, the South Platte River remains a world-class trout fishery abundant with some of the most finicky and challenging trout in the world. The picturesque, boulder-filled Cheesman Canyon section of the South Platte River is one of the prime stretches. From the base of the 221-foot Cheesman Dam, the river carves its way through a rose-colored granite canyon lined with ponderosa pine, blue spruce, and willow. Boulders as big as Volkswagen Beetles create structure for the river’s super-selective rainbows and browns. Mule deer, black bear, raccoons, mountain lions, rare butterflies, sagebrush lizards, and bald eagles all add to the experience.
Hayman Fire
The Hayman Fire was the largest fire in Colorado history, burning more than 137,000 acres in four counties. The area surrounding Cheesman Reservoir was completely devastated and sediment flowing into Cheesman Canyon is a major concern. After the fire, the stream bottom became a graveyard of ash, soot, and silt. The water was gray and as thick as hydraulic oil, and the denuded landscape was left vulnerable to erosion and flash floods.
High flows in the fall of 2003 helped free the center channel from the silt, soot, and ash, and the river began to clear. As the autumn season after the fire unfolded, I was astonished to see that the insect life below Cheesman Dam was thriving. Trout eagerly rose to significant numbers of midges, Tricos, and Blue-winged Olives, and anglers reported exceptional dry-fly fishing.
The Colorado Division of Wildlife did its annual electroshocking in the fall of 2003, and, to everyone’s surprise, the fish count revealed that there were more fish in Cheesman Canyon than the previous year. The trout somehow survived the off-colored water, and to date they’ve shown no signs of stress. The thick-bodied rainbows are healthy and strong, and if you didn’t know any better, you would never suspect that they lived in almost unbearable conditions throughout the summer of 2003. These fish continue to fight against all odds, and their instinct to survive has amazed everyone.
I expect that torrential downpours will be a problem for the next several seasons. Ash, soot, and silt—two feet deep in places—still clog the edges of the stream and flow fluctuations will continue to change the clarity of the stream for several years. Between May and August, heavy rains may wash debris into the river, changing the fishing conditions. Each time it rains, less and less debris is washed into the river. The South Platte will eventually rebound, but it will take time and positive conditions.
Whirling Disease & Snails
The South Platte River was a self-sustaining rainbow trout fishery until the appearance of whirling disease. In the glory days, Cheesman Canyon boasted 5,500 fish per mile, with the bulk of the trout being impressive-size rainbows.
Brown trout now fill the void where rainbows once thrived. According to a fall 2004 electroshocking survey, there are 3,700 to 3,900 trout per mile in Cheesman Canyon with a 70/30 ratio of brown trout to rainbow trout in the lower canyon and 50/50 ratio in the upper canyon.
In April of 2005, New Zealand mud snails were discovered in the South Platte River upstream of Cheesman Reservoir. Only time will tell how this invasive species will affect the fishery.
A Day’s Fishing
I typically begin a day’s fishing from the lower end of Gill Trail. You should stock a backpack with supplies for your trip into the canyon. Items you should consider are water, lunch, first-aid kit, sunscreen, rain jacket, and your normal fly-fishing apparel. I recommend wearing waders because the water is very cold.
I hike in with all my fishing gear in my backpack and suit up at the river. Since the walk is rigorous, hiking in your waders and vest is uncomfortable, especially if you plan to fish the upper canyon.
An ideal flow regime for Cheesman Canyon is between 250 and 400 cubic feet per second (cfs). Winter releases (November-February) average between 50 and 75 cfs. Anything over 700 cfs is high, and the fast, roily currents make for difficult fishing.
After I make my way into the canyon, I choose my fishing location mainly based on the current releases from Cheesman Dam. There are constricted areas (such as Lower Narrows, Hell’s Half Acre, Upper Narrows) that fish best during lower flows. The wider sections of the stream (such as Meat Hole, Steel Riffles, Rocky Road, Cleo’s Camp, Indicator Pool) fish best when flows are higher than 250 cfs. Don’t get trapped into fishing the same hole over and over again based on prior success. This rationale limits your growth as an angler.
Summer (June-August)
May and June are typically the start of runoff and higher than normal flows, which can range between 600 and 1,200 cfs. In some cases Cheesman Reservoir “spills” (part of the water comes over the spillway), and water temperatures rise because of the warm surface water flowing over the spillway. If this occurs, the fish move into fast, oxygenated water until the water is once again drawn from the bottom of the reservoir. This is the best time to fish aquatic worms and scuds because they get dislodged as a direct result of the increased water volume.
There is a three- to four-week period during runoff that I call the “stupid period” because the fish eat anything that resembles a worm if dead-drifted correctly. In time, the trout get wise to these worm imitations, and worms tend to work best early in the season during the high flows. I switch to a small version of a San Juan Worm (tied on a #18 scud hook with micro chenille) when the trout become suspicious of larger versions.
Beginning in mid-May, you’ll see sporadic caddis hatches. The best time to experience this surface action is during the late afternoon to the evening, when the fish are “looking up” in shallow riffles and pockets for caddis. A #16 Elk-hair Caddis can be effective in the last two hours of daylight.
Throughout June, pale olive midge larvae become important between 8 and 11 A.M. Cheesman trout are stuffed with these larvae this time of year. To imitate these midges, use 8/0 Light Cahill thread on a #18 scud hook and gold wire for a rib.
Copyright © 2012 Intermedia Outdoors
Comments