South Platte - Canyon
If you like site fishing to big rainbows, Cheeseman Canyon is about as good as it gets. Among the rivers mentioned on this site, this is your best chance of landing a picture fish. In 1976, this stretch of river was the first in Colorado to be designated as catch and release (Gold Medal Water) and it has maintained that quality since. Although the trout population has declined since then, the canyon is still home to some trophy rainbows and a few healthy browns as well. The fish here can be extremely finicky but they are not shy; don’t be surprised if you see three and four-pound rainbows swimming around your feet! Despite the rigorous hike along Gill Trail, this remains a popular destination for fly fisherman around the country, so don’t expect to be the only one here. However, being on the river at sunrise will usually allow you a choice of fine fishing spots.
As the name would imply, this is a canyon setting with stone walls and steep, loose rock banks. Gill trail runs the length of the canyon from family pool up to the cheeseman reservoir outlet. The easiest access is just up the road from Deckers; you’ll see a small dirt parking lot on the right just past the private drive for the Wigwam Club. If that is already full (which is quite common), continue up the road about another 300 yards and there is a parking area on the left next to the road up to Cheeseman; this upper parking area will add about 10 minutes to the hike. You can access the upper canyon via Gill trail or by parking at Cheeseman and taking a long hike to the dam. I made the mistake of trying this route once! The walk down to the river was long but not all that strenuous. After fishing a few hours, the walk back was a workout. If you try it, I would advise putting your waders and boots in a backpack and wearing shorts and comfortable shoes for the walk. I prefer walking up the trail, which will take you to the same place and you’ll be able to fish along the way.
Line control and stealthiness are of the utmost importance in the canyon as the water here is extremely clear. I would suggest no less than 10-foot leaders (12-foot being preferable). Your 2-3 foot tippet section should rarely get larger than 6X, although you can get away with 5X flourocarbon material. Take your time and scout the water before jumping in; if the fish see your shadow or fly-line you may have already lost the battle.
The canyon can be fished year-round although Gill trail can get icy and snow-packed. During the winter months, midge larvae are the flies of choice. Small (#22-26) disco, black beauty, and brassie patterns are good selections during this time. By late March, blue-wing olive activity picks up but the hatches are not predictable; in my opinion, the midge hatch is more reliable. RSII’s and loop-wing patterns work well before and during the mayfly hatch along with the comparadun. If you don’t see any mayfly activity, fish flashback pheasant tails and bwo nymphs in the riffles and tailouts. Griffith’s gnats and other small, dry midge patterns will also catch fish as the water begins to warm in the spring. As the flows pick up in May and June, try scud and san juan worm patterns with enough weight to get them down in the swift currents. When the flows begin to recede in July, caddis activity picks up. Buckskins, pupa patterns, and hare’s ear nymphs are good choices for caddis imitations. The trico hatches in August and September can be the most fun and also the most frustrating. The most action occurs when the tiny insects return to water around mid-morning (9:30-11:00). Spinner patterns in sizes 22 and 24 have been the most successful patterns for me. When those fail to draw strikes, I try the double winged patterns. In September, bwo’s will return in the mornings and can provide great fishing in the evenings during the spinnerfall. Loop-wings, foam-wings, and RSII’s are good selections for emerging patterns. Spent-wing bwo’s in light olive and grey work well in the evenings. Fishing with terrestrials seems to be more effective in the Deckers area, but black ant patterns will fool the occasional canyon rainbow.
There are numerous patterns that seem to be tied specifically for this river. You can improve your fishing success by calling a local flyshop or stopping by Flies’N’Lies in Deckers to see what patterns are currently the most effective.