CODY - A short hike into a scenic canyon in Cody leads to an oasis of gin-clear waters abuzz with hatching flies and dimpled with rising trout.

During the dog days of winter most Wyoming rivers are frozen over or so cold the fish don't want to bite. Not so at the Lower Shoshone River.

A steady flow out of Buffalo Bill Dam, and hot springs bubbling in various spots, keep the river moving through the town of Cody at a fisherman-friendly water temperature throughout the long months of winter.

Fly anglers here have more than four miles of public access to roam to get in a winter fix of great fly fishing. The river is chock-full of trout - mostly wild browns and rainbows in the 14- to 16-inch range, with some stocked cutthroats and brook trout too.

Hatches of tiny midges and mayflies peak in the afternoons, often sending the river's fish into a feeding frenzy in almost any weather. Don't bother with the typical winter fly-fishing tactic of dredging the depths with wet flies and nymphs. Instead, tie on a dry fly to catch fish on the surface like it's the middle of summer. You'll know where to cast when you see the bellies of fish rolling on the surface of the water as they gobble down hatching bugs.

"The fish are generally in a good mood," said Tim Wade, owner of North Fork Anglers flyshop in Cody. "They eat all the time like that. That's why they're so fat."

The Lower Shoshone is unusual in that its best fishing is from October to April. That's when the river is flowing at a nice and easy 150 cubic-feet-per-second out of the dam. But come springtime, the dam's output is raised for irrigation season and the river swells to a fast and furious rate for several months.

With a daily smorgasbord of aquatic insects to choose from, the river's fish can get persnickety. They can spot fly line from a mile away and you have to drift your bug perfectly or they'll ignore it. They'll test your patience and darn near drive you crazy as you watch them gulp down live bugs inches from your fly on cast after cast after cast.

But eventually a fish hits your fly and the fight is on.

Some of the best match-the-hatch fly patterns are para-duns, parachute olives, snowshoe olives and Griffith's gnats in hook sizes from No. 18 down to a tiny No. 24. Keep switching fly patterns - and hook sizes - until you find the one that works.

"The best dry-fly fishing on the river is in the winter, particularly if you like to match wits with the fish. Sometimes you win, sometimes they win. That's what makes it fun," Wade said.

Although the water stays a cozy temperature for the fish, the elements for a fisherman can be bone-chilling, even dangerous, so bundle up and watch your step on the riverbanks which can get icy.

A fly angler who's willing to brave the cold, wintry wind that often howls through the canyon is usually rewarded with mile after mile of solitary fishing on the Lower Shoshone. There's rarely more than a handful of anglers at the river during winter. Some days you might have the whole place to yourself.

"Most people this time of year are up at Buffalo Bill Reservoir drilling holes in the ice. It's a lot easier to catch your limit sitting on a bucket than fly fishing in the wind and ice," he said, adding that he encourages fly anglers on the Shoshone to release their catches.

"A wild trout's too valuable to be caught only once."