Stream modifications include narrowing the stream, creating deeper pools on outside bends, stabilizing point bars and banks, and placing structures across streams to create pools behind them and get the streams to start doing what they were designed to do.

"In the early '90s, that segment below Spinney Mountain Reservoir started to be impacted with whirling disease, very much so through the late '90s," said Gerlich. "We essentially lost all rainbow recruitment. Through an aggressive stocking program, we brought in larger rainbows and also tried to beef up the numbers going into Elevenmile Reservoir. We managed to bring back the good component of rainbow and cutbow fisheries that are in there." A cutbow is a hybrid created from cutthroat and rainbow trout. The resilient brown trout has not suffered.

Habitat improvement has coaxed cutbows to make spawning runs upriver from Elevenmile Reservoir. "Twelve- to 18-inch cutbows used to run up the river in a spawning run. Whether or not they were very successful at spawning -- probably not -- they were thinking they were going to do that. They would return back down to the reservoir, because there wasn't much good holding habitat for them up there, but now there is. We are seeing an increase of biomass, particularly in that segment."

Below Elevenmile Reservoir is Elevenmile Canyon. The canyon is about eight miles long and is accessible out of the town of Lake George, Colo. On the upper segment of the canyon, about three miles, only flies and artificial lures are allowed. Most of the rest of the lower canyon operates under standard regulations. Colorado DOW supplements the rainbow trout populations with stockings in late spring and early summer.

Elevenmile Reservoir has larger than average rainbows, cutthroats and browns. Some of the biggest kokanee salmon in the state are caught out of Elevenmile. Spinney Mountain Reservoir is touted as the place to consistently catch 16-inch-plus rainbows, browns and Snake River cutthroats. The best fishing is right after April ice-out. Anglers can fish from belly boats or the shore.

Upstream from Hartsel, Colo., habitat improvement work was completed on the South Fork. "What we see in there is a good standing population of brown trout as well as more holding cover, more increased numbers of rainbow trout," said Gerlich. Standard fishing regulations apply for this section, not limited to artificial flies and lures.

In addition to the trout in the South Platte and its forks, Colorado anglers will find the biggest rainbows in the larger reservoirs, starting as early as March in the lower elevations and going into April and May.

Chatfield Reservoir, on the south end of Denver, offers fishing for large rainbow trout. Moving upstream to the next reservoir is Strontia Springs. The segment below it, commonly known as Waterton Canyon, offers activity on bigger rainbow and cutbow trout.

A wide variety of dry flies and nymph tactics are used. Many anglers use a trailer fly, such as a caddis or nymph behind a dry fly. Other anglers use spinning-rod tackle. "We have some folks who use smaller tube jigs," said Gerlich. "Anglers should refer to the new 2006 fishing regulations booklet pertaining to the sections of streams they will be fishing. Most of them are signed well, but it's good to check whether you're in a fly- and lure-only segment."

ARKANSAS RIVER BASIN
The Arkansas River offers nearly 80 miles of public access, from Hayden Flats near Leadville to Canon City, and boasts high catches of browns and rainbows to 20 inches. Browns dominate the fishery, but large rainbows are common.