A great mystery attaches to the river that runs into Wardensville, W. Va., as it probably should to any river called the Lost.

This is good, because the mystique and unpredictablility of the Lost scares away most would-be users, leaving it for the few with an adventuresome bent. And nothing is better than having a superb white water river almost to oneself.

The bible for fast water paddlers in the Washinton area is called "Canoeing Whitewater River Guide." It was written by the late Randy Carter some years ago and it helps perpetuate the myth of the Lost.

In Carter's trip description he writes, "Start at Rte. 55 bridge where the Lost River sinks into its bed and goes under Sandstone Mountain to emerge five miles further downstream.

"This run can only be made in high water. Only in high water can one navigate the flood channel the river used before it found its way under Sandstone Mountain. When the river is up about two feet above normal about half of the water goes underground and the other half runs through the gorge."

Manuel and pat munoz, fearless Washington white water paddlers, heard the tales about the Lost and were intrigued by this disappearing river.

They weren't afraid of getting washed into some underground cavern, and they were doubly interested when they learned Carter rated the rapids in the Lost gorge as Class 3, 4 or 5, depending on water level.

Class 5 rapids, according to the American Whitewater Association, are "long and continuous, tortuous, require frequent scouting. Extremely complex course. Waves large, irregular and unavoidable. Large-scale eddies and cross-currents. Rescue spots few and far off. Special equipment required -- decking, life jackets."

Off went the Munozes to paddle the Lost in undecked boats several springs ago. They've been paddling it two or three times a year ever since with boundless satisfaction.

They found rapids that might not be quite Class 5, but were close. They found a scenic, gorgeous gorge.

The only thing they haven't found is this place where the Lost allegedly disappears, or the place five miles below where it supposedly reappears.

"It gets dry in the summer, lke any river, and you can't paddle it," said Manuel Munoz. "But we have never lost the Lost."

That is not a fact they share with everyone that happens by.

Last week they took a foursome of quaking novices along for a lost run, assuring them all along that it was not nearly as perilous as the books made out.

At the put-in near the Rte. 55 bridge outside Wardensville they were gathering up equipment for the start of the run when a camouflage-painted Volkswagen with two canoes on the roof appeared. A yound man jumped out and ran down the hill.

"Are you just taking out?" he asked.

"No," said Munoz. "We're putting in."

"But there's no river down below. Where are you going to go?"

"Hummm," Munoz said, deadpan. "No river? Then I guess we are in very bad trouble."

The stranger shook his head and walked away, presumably to spend the day on some river that really existed.

He should only know what he missed.

The Lost is an incredibly perfect whitewater stream when the water level is right, as it was last week. "Frankly I hate to take people on it." said Pat Munoz. "It spoils them for ever."

It's a narrow chute through mostly high, rocky gorges, and this time of year the banks are aglitter with blooming wild azaleas. Not that there's much time to enjoy the scenery.

The Lost is rapids after rapids after rapids, with only brief intermissions in deep pools.Some of the rapids are ones that would shake Mark Trail, but because the river is narrow and "intimate," to use Pat Munoz's word, the dangers are somewhat limited.

It would not be hard to destroy a canoe in the Lost, but you'd have to work to endanger life. The shore is never far away.

It's a river that puts a premium on delicate, precise maneuvering of a canoe, not raw power. There are frequently only tiny slots through massive rock formations and tumbling whitewater, and the canoe must find the slots or it won't get through.

Pat Munoz is a master at that kind of paddling and it was a pleasure to share a boat with her.

She deftly nudged the bow from safe place to safe place while I thrashed around in the stern, whooping and howling when the water sloshed over the gunwales.

It was a stirring trip, marred only by two harmless capsizes among out three boats.

And best of all, we say only four other paddlers. They must have been Lost, too.

Water level is critical for paddling the Lost. Pat Munoz spent three days before our journey making calls to assure there would be adequate water.

She said the best gauge seemed to the the report from the Kootes Store river gauge on the north Fork of the Shenandoah, which is not far from the Lost.

"The reading at Kootes Store must be above 2.9 feet," she said. "When it's five feet at Kootes Store the Lost is considered high, and at 5.5 feet it's considered risky."

The Kootes Store reading is available to Washingtonians on a telephone recording, along with a number of other river-level readings. The phone number for the recording is 899-3210.

There is also a gauge at the Rte. 55 bridge over the Lost, put there by Randy Carter. He contends the river is too low to run at anything below 1 1/2 feet on that gauge, but we marked it at three-quarters of a foot the day we went and found that to be ideal.