The Colorado River is the main watershed for much of the American Southwest. It runs 1450 miles from high in Colorado’s Rocky Mountain National Park to its delta in the Gulf of California near Sonora, Mexico. The upper portion of the river from Granby, Colorado to below the town of Rifle is an excellent trout fishery that holds a healthy population of brown, rainbow, and native cutthroat trout. Most of our fishing trips to the Colorado are with either a drift boat or raft because it is a large, deep waterway with roaring rapids, steep canyon walls, and treacherous, rocky banks. The rugged beauty of the Colorado River is unmatched, and is sure to inspire and captivate even the most seasoned fly fishermen.
Sections of the Colorado
The section of the Colorado River that we focus on stretches over one hundred miles from near the town of Kremmling, Colorado all the way to the town of Rifle. There are three main sections of river within this stretch - the upper, middle, and lower. The upper river runs from the confluence of the Colorado River and the Blue River through Gore Canyon down to the small outpost of State Bridge, Colorado. This stretch is considered by some to be the most scenic and best-fishing stretch of the entire river. It's cold, clear water is the ideal habitat for trout and aquatic insects alike. The middle river runs from State Bridge to the town of Dotsero where it joins the Eagle River. Here, grasshoppers sing and big brown trout smack the surface as the water slows down and meanders through massive red rock canyons and wide open ranch lands. The lower Colorado river begins at Glenwood Springs and runs west along I-70 to Rifle. This stretch fishes best during late fall and through the winter and can hold monster rainbow and brown trout.
Seasons of the Colorado
Fishing season on the upper Colorado River usually starts in late May and early June when the first salmonflies begin to flutter. River flows can be very high this time of year and the water can be very muddy, so it is sometimes better to fish this hatch on foot. While float fishing is possible at any level, it really turns on once the river drops below 2500 CFS in Kremmling. This usually happens sometime in late June or early July, just in time for the summer hatches of caddis and mayflies.
The summer float season on the upper Colorado River offers some of the most consistent fishing of the year. With grasshoppers, caddis, sculpins, and a variety of mayflies in the water on any given day, hungry, surface-feeding trout are usually easy to find. The hopper-dropper is the rig of choice for most guides on the Colorado River through the summer and early fall, with fish eating above and below the surface all day long. During the middle of the summer, many parts of Colorado experience a monsoon season that brings regular afternoon thundershowers. These daily storms deliver much needed cold water to the Colorado, but they also deposit large amounts of sediment into the river. Clear water on the middle and lower sections of river can be scarce during the monsoon season, so many fishermen spend their days on the upper portions of the river to avoid the mud.
As the summer turns to fall, the weather usually stabilizes a bit and the water clears up throughout the whole river. This can be a challenging time of year to fish because of the brown trout spawning season, but with a little patience and the right combination of bugs, big fish can still be caught during the fall fishing season. This is also the time of year that the lower river’s temperature falls back into an acceptable fishing range.
Throughout the coldest parts of the winter, much of the upper Colorado river freezes solid. Open water on public property can be difficult to find, and hungry fish can be rare. Most Colorado River winter fishing trips take place on the lower river below the confluence with the Roaring Fork at Glenwood Springs. Here, midges flutter and dance along the water’s surface almost every day, and eager trout often rise to the surface to sip them down. Most anglers prefer to fish the lower Colorado from a boat, meaning that there is not very much competition for wade fishing spots. Wade fishing on the lower Colorado can be very productive during the low flows of winter and early spring. Subsurface rigs work best, but the patient angler can, with a little luck and the right weather, catch fish on dry flies here and there through much of the winter season.
Like always, be extra careful not to fish or walk over brown trout or rainbow trout spawning habitat while fishing the Colorado River during both spring and fall spawning seasons. Pay close attention especially while fishing near confluences and be careful to obey the seasonal closures at Canyon Creek, Grizzly Creek, and No Name Creek. Fishing is prohibited in these areas from March 15th to May 15th and again from October 1st to November 30th.
The most anticipated event of the year on the Colorado River is the emergence of the Salmonflies in early June. This is when insects the size of small birds flutter and dance on the water’s surface and hungry brown trout charge after them with reckless abandon. Good timing is critical when fishing this amazing hatch. It usually begins around the time that the water temperature rises to 50 degrees Fahrenheit and lasts under a week. If you happen to find yourself on the banks of the Colorado River during the Salmonfly hatch and see huge brown trout crashing the surface, prepare yourself for a day of fly fishing that you won’t soon forget.
The Colorado River is a world class trout fishery and a real treasure for anglers and boaters of all abilities. Before you head out to the Colorado, make sure to stop by the fly shop and chat with one of the expert shop staff or pro guides at Vail Valley Anglers. There you can get valuable information about current fishing conditions and hatches as well as the best flies, tackle, and gear in the valley.