ON THE SNAKE RIVER, Ore. - A white wall of water smashes against the 40-foot jetboat as it zigzags across the mighty Snake River, sending it careening toward a rock the size of a bus.
Go left! The pilot cuts the boat against the rushing current - this time in the other direction.
Look right! A giant curl of icy water hits the deck.
"Eeeow!" yells Mary Naylor, one of 20 passengers hanging on for dear life as the jetboat slams against the white swirls - sending it up and down, up and down - until the boat cuts left again and returns to calmer currents.
Ms. Naylor - grinning - wipes water from her face.
"That went just the way I planned," laughs veteran pilot Bret Armacost.
Welcome to Granite Creek - one of two of the most treacherous rapids along the lower Snake River in North America's deepest river gorge, Hells Canyon. This out-of-the-way stretch of river is a haven for lovers of the rugged outdoors willing to take the time to get there.
Boats are launched just north of the Hells Canyon Dam - about a 2´ hour drive from Baker City, Ore., and 3´ hours from Boise, Idaho.
The Snake River begins in Yellowstone National Park and meanders for 1,035 miles through Wyoming and southern Idaho - then north to form the boundary between that state and Oregon. Finally, it enters Washington and turns southwest to join the Columbia River.
The river's name is said to have come from the Shoshone Indians, who painted snake heads on their weapons and used a wavy hand sign to identify themselves.
Hells Canyon is the section of the Snake stretching from the Hells Canyon Dam northward for 74 miles to Cache Creek on the Oregon-Washington border. It is largely inaccessible except by river raft.
Measuring a mile-and-a-half from the river bottom to the tallest peak of the Seven Devils Mountains, the canyon's shoreline widens and narrows, alternating between huge, half-submerged boulders and grassy beaches.
Deep canyon walls, strikingly barren, rise almost straight up from the water. Where the river is wider, the bluffs are green and rolling. The water thundering through the canyon is mostly white - rapids following rapids.
Mr. Armacost, who has run this river thousands of times over the past 22 years, knows every twist and turn, every treacherous rock and current.
"You need to have respect for these rapids," he says.
Mr. Armacost and his German-born wife, Doris, own and run Hells Canyon Adventures, the only jet-boat operation licensed to run Hells Canyon. They say they take about 7,000 passengers down that stretch of the Snake each year.
During the summer, the Armacosts run two-, three- and six-hour jetboat rides, as well as an overnight trip. They also offer a daylong white-water rafting trip.
Other commercial riverboats on the Snake run out of Lewiston, Idaho, and Clarkston, Wash.
It's worth the drive from Boise - the latter part on a narrow highway fraught with hairpin curves but offering views of the sheer rock drop into the canyon.
The largest - and most treacherous - rapids are in Hells Canyon. And the Armacosts regularly navigate through two of the most perilous - Granite Creek and Wild Sheep, both rated level-four rapids.
According to the book Hells Canyon: The Deepest Gorge on Earth, by William Ashworth, Granite Creek is exceeded only by Lava Falls on the Colorado River. The river itself, he writes, is more than three times the length of the Hudson River and almost twice the volume of the Colorado.
The Armacost's passengers are treated to views of wildlife climbing along the canyon's steep slopes - bighorn sheep, deer, lynx, river otter - and now and then, even a bear.
On Ms. Naylor's trip down the river, a pair of Bighorn sheep sparred on the rocks. The herd scrambled up the cliffs as the roar of the jet boat neared. But Mr. Armacost cut the engine - letting passengers listen to the clacking horns as the two battling sheep rammed.
The Armacosts also take passengers on a short hike up to a niche in the rock decorated with ancient Indian pictographs.
Rafters also stop at an isolated old homestead, tucked away above a swift stream feeding into the Snake River. The tiny home - which at one point housed a family of 11 - is built entirely with short planks hauled in by horse.
These waters are seeped with tales of the Old West.
In 1887, a group of Wallowa County men - apparently jealous of a group of Chinese miners who had found gold - killed and mutilated more than 30 men. They loaded the bodies of the murdered Chinese in a boat, which they sent down the river. Local newspapers called it the "crime of the century." Six men were tried for the murders but were acquitted.
The book Snake River of Hells Canyon, by Johnny Carrey, Cort Conley and Ace Barton, documented a story that originally appeared in an 1895 edition of McMurdy's Marine History of the Pacific Northwest. According to the story, the stern-wheeler Norma was in the mouth of Deep Creek when the boat "bounded off, swinging into midstream, and, like a racehorse, shot into Hells Canyon, where the river winds like a serpent and the wall rocks tower to such a height that they almost shut out the sun."
For the Armacosts, this rugged river is a way of life. They bought the boat business in 1992. Since then, their fleet has grown to three custom-built boats - 28, 36 and 40 feet long.
"We love the river - and we want to keep it the way it is," Mrs. Armacost says.
BOOKING A TRIP:
Hells Canyon Adventures offers a one-day whitewater rafting trip and jet-boat tours of two, three and six hours, as well as an overnight trip. During the summer, jet-boat tours don't run every day because of certain restrictions. Call (800) 422-3568. The company's Web site is http://www.hellscanyonadventures.com/. About 15 other small companies run white-water rafts through Hells Canyon. They can be reached through the Hells Canyon Visitor Information Center at (541) 742-4222.
Jet-boat tours range from about $30 to $95 per day trip. Overnight trips are $250. White-water rafting trips are $140 per person. Hells Canyon Adventures offers off-season rates and lower rates for children.
There are a number of places to stay, ranging from campsites to bargain motels and a couple of quaint bed-and-breakfast inns in nearby Oxbow and Halfway. The Armacosts, who operate Hells Canyon Adventures, also operate a small bed-and-breakfast. A good resource is the http://www.half.com site, which has more than 60 links to motels, restaurants and businesses in the area. For help finding lodging, call the Hells Canyon Visitor Information Center.
WHAT TO WEAR:
During the summer, the water is warm enough to swim in, so bring swimwear, a hat, sunscreen and shoes that you don't mind getting wet. The canyon can get cold during chilly spring months, though, so bring a hooded jacket to protect your ears and keep water from running down your back. Gloves will help keep your hands from going numb and secured sunglasses can help keep water out of your eyes. Also bring a waterproof camera with a string to wear around your neck and dry fleece, a towel and shower supplies for after the trip.