Gary Soderlind flicks his fly line into the upper Rogue River, then he whips the excess line upstream and watches his bobber-like float dribble through the riffling water.

Gary Soderlind flicks his fly line into the upper Rogue River, then he whips the excess line upstream and watches his bobber-like float dribble through the riffling water.

The float quickly drops under the surface as a summer steelhead tugs at one of his heavily weighted nymph flies — an egg-sucking leech. So Soderlind jerks the rod to form a straight line between the fly-fisher and his quarry.

"Get ready. He might jump," Soderlind yells to his fishing partner, Jeff Fish.

But Soderlind's line quickly goes slack. Freed from the fly, the steelhead jumps downstream in water bathed in an orange sunset.

"Damn," he says, recasting his nymphs. "Let's do it again.

"I've been nymphing all year long like this because we've been catching fish almost every time out," Soderlind says. "Why change?"

Those not nymphing now on the upper Rogue better consider otherwise because going deep is the method du jour for fly-fishers looking to increase their chances of catching summer steelhead during the tail end of this fall's flies-only season.

A combination of natural and artificial conditions now in the upper Rogue make traditional streamer-fly fishing near the surface virtually moot, leaving success to those who get the right flies down to the riverbed where steelhead lie.

The river is artificially cool now thanks to colder-than-normal releases from Lost Creek dam to improve conditions for summer steelhead eggs incubating in upper Rogue gravel beds.

That cool water slows the summer steelhead's metabolism, rendering them less apt to rise to a streamer skating at or near the riffle's surface — the steelheader's angling method of choice during warmer summer conditions.

And why should a steelhead even bother with some sexy-looking streamer near the surface 6 feet away when so many loose eggs from spawning fall chinook now come dribbling right past its mug all day?

This combination makes casting combinations of weighted flies — as many as three on one line — creates the best chance to catch steelhead until more conventional gear becomes legal again Nov. 1.

"Right now, it's strictly nymphing," says Dave Roberts, an Eagle Point-based fly-fishing guide.

When in freshwater, steelhead act mostly like their close cousins, the rainbow trout. They are active feeders and are their friskiest in water temperatures between 55 and 60 degrees, and more than 80 percent of their diet is insect larvae below the surface.

During late summer, summer steelhead are very willing to attack streamers such as red ants and tiger paws swung in the top 3 inches of water.

But in late September through early October, the U.S. Army Corps of Engineers starts reducing its water-release temperatures. Flows out of Lost Creek Lake, for example, bottomed out this week at a chilly 45 degrees — 9 degrees cooler than the 55-degree water flowing out of the lake's sister reservoir, Applegate Lake.

The reason is to offset the warmer-than-natural winter flows in the upper Rogue because of the sun's effects on the lake. Spring chinook eggs incubate based on water temperatures, and not releasing colder water now would trigger late winter hatch-out times that don't favor spring chinook survival, according to Oregon Department of Fish and Wildlife studies.

Though altering the fishing strategies of anglers is not intended by the change in water temperatures, it is inevitable.

"During most of September and October, if you're smart, you fish wet flies," says Tom Satterthwaite, the ODFW biologist who conducted most of those water-temperature studies.

Anglers sich as Soderlind have it down pat.

Upper Rogue angling rules allow for three flies, but most anglers use two and fish them on a 10-foot leader.

One fly, called the "dropper," usually is a heavily weighted stonefly imitation such as an Ugly Bug. Tied 18 to 24 inches below that is what is called the "point" fly — usually a single egg pattern.

Along the leader is a strike indicator or a similar bobber-like float.

The dropper fly acts like a legal weight to draw both flies to the bottom. The steelhead normally bites the egg pattern, and the strike indicator plunges when that happens.

Using gear borrowed from Soderlind, Fish hooks his first steelhead on a fly in textbook fashion.

It, too, bursts downstream and unbuttons itself from Fish's fly.

"Wow, he was hot," Fish says. "It's sure got my adrenalin going."

Casting multiple, weighted flies isn't pretty. Casts are more like lobs in a true chuck-and-duck fashion, so a weighted hook doesn't tear into the back of your head.

"The fly does what it wants to do in the air," Soderlind says.

Casts travel upstream at a 45-degree angle in riffles, mending the line to get as drag-free a drift as possible. That drives the flies down the water column and into view of hungry steelhead busy slurping free-floating salmon eggs downstream from spawning beds.

"I figure you need to get a pretty good-looking fly and get it near them," Soderlind says. "That's why I fish this way, and I'm not going to stop."