A grayish-green salmon darts across the golden cobblestone bottom of a quiet pool along Idaho's famed Selway River.

An osprey flies its patrol over the wilderness river in early August, screeching amid light and dark green mountainsides covered with tall pine, lacy cedar and mossy rocks.

For a moment, Allen Powers of Boise rests in his inflatable kayak in the serenity of the pristine Selway, a river that is considered one of the last remnants of primitive America.

The next minute, his kayak and other rafts are crashing through boulder-strewn rapids with 3-foot waterfalls.

Oars smash against rocks. The bows of rafts hit truck-size boulders head on and boomerang in all directions.

Welcome to Idaho's most coveted whitewater run.

Running the 47-mile wilderness section of the Selway River in northern Idaho in low water is part rock-climbing, part bouldering, a lot of rope work and plenty of strenuous rowing and paddling.

But if you are going to do it outside the controlled summer season when you don'tneed a permit, you go for it, no matter what.

ONE-GROUP LIMIT

To keep the Selway as pristine as possible, the U.S. Forest Service allows only one party to launch per day through the high-use season from May 15 to July 31. The maximum party size is 16.

Floaters have to apply for permits in a highly competitive drawing each winter.

In contrast, seven parties are allowed to launch each day on the Middle Fork of the Salmon River in the Frank Church River of No Return Wilderness, which is another world-renowned river. A party can be up to 30 people.

The limited permits for the Selway are designed to protect the wilderness qualities.

Powers found that serenity floating over the rivers quiet pools.

"Part of the beauty and magic of the Selway experience is the amazing palette of shimmering colors in the water beneath you," said Powers.

Not many people get to see the remote Selway. Only 723 people floated the Selway in 2007. In comparison, about 10,000 people float the Middle Fork of the Salmon River.

River rats Dave Hopkins and Corrine Christ of Boise chose to float the river after the permit season in August and were glad they did.

"The memories of this precious and privileged experience I will treasure forever," said Corrine Christ.

Other boaters also took on the Selway's low water. When the end of the permit season comes in August, whitewater boaters who were unsuccessful in getting a permit for the summer season converge on the river.

On Aug. 1, 20 parties consisting of about 114 people, were at the Selway launch site.

The remoteness and difficulty of the river and logistics of putting a trip together keep most floaters out.

Low water is especially difficult. Long scouts on rapids and pushing and pulling rafts over rocks can mean long days. At one point, the group Powers was in took five hours to go five miles in the upper stretches of the river.

THE LAND

It is worth it because the Selway is a unique wilderness. It is is locked in by the high ridges of the Bitterroot Mountains and deep canyons blanketed by thick forests.

You quickly notice that the land is so unlike other parts of Idaho. About 1.3 million acres of the Selway-Bitterroot country was designated wilderness in 1964.

It has diverse vegetation and terrain. The coastal-type vegetation is surprising. It includes old-growth Western red cedar, ferns and lots of moss.

The six-day wilderness float trip takes rafters and kayakers from U.S. Forest Service's ranger station at Paradise to the end of the road just above Selway Falls near the river burg of Lowell.

There are few lodges and ranches along the way, contributing to the wilderness solitude.

THE RAPIDS

And don't forget the rapids. At low water, Galloping Gertie, Washer Woman, Wolf Creek, Ladle and scores of other rapids have sharp teeth in the way of rocks.

It could mean wrapping rafts on rocks, getting perched on boulders, pushing rafts over boulders and sometimes cutting the bottom out of rafts to get them off rocks.

Repair kits are worth their weight in beer because of the sharp rocks in the river.

Rafters in August are weight-conscious, opting for a lot of dried foods and also subbing the hard stuff for beer.

If this sounds discouraging, it isn't for a rare opportunity to run the Selway.

"It's the challenge of the river and the beauty of wilderness," said Hopkins.

Pete Zimowsky: 377-6445