KETCHUM- Tony Foster has long enchanted Wood River Valley residents with his watercolors of volcanoes, icebergs, rainforests, mountaintops and deserts painted on site around the world.

Now Foster fans can curl up with a 324-page coffee table book of Foster's work and read about his adventures at the same time they peruse his colorful, often detailed paintings.

"Painting at the Edge of the World" was published in conjunction with Foster's exhibition, "Searching for a Bigger Subject," which contrasts two of the world's extremes - Mount Everest and the Grand Canyon.

It features the British painter's "watercolor diaries," which he wrote as he painted, and many of his paintings.

The book, which includes a forward by Robert F. Kennedy Jr., is available in three luxurious editions. The standard edition costs $75. A limited edition presented in a handmade slipcase is $280 and includes a limited edition giclee print of 250 copies signed and numbered by the artist.

A collector's edition, in an elegant handmade clamshell box, costs $2,500 and includes an original watercolor suitable for framing from a choice of five subjects: Desert, rainforest, mountain, canyon or volcano.

"This book has been a lifelong idea of Tony's," says Ketchum gallery owner Gail Severn, who helped underwrite the costs of the book. "It's a phenomenal read - he's an exceptional artist with an exceptional body of work. And he's an explorer-artist in the true tradition. His painting expeditions take huge amounts of preparation and expenses."

A resident of Cornwall, England, Foster began his visual diaries in 1982 when he retraced the steps of 19th-century writer Robert Louis Stevenson's journey through the French Pyrenees in the mid-1800s.

He followed that up with a trip to Walden Pond, carrying a paint box the size of a deck of cards, watercolor paper in a tube made from plastic drainpipe and a folding plywood desk.

Over the years, he has canoed through the rainforest, hiked 400 miles through the Grand Canyon, trekked 18,000 feet up to paint Everest and rafted along the Salmon River - stopping for tea every two hours, of course.

He's painted in falling snow and rain, battled bee stings, mosquitoes and altitude sickness and spent hours knee-deep in mud and sitting on a pointed rock he later dubbed "Numbum Rock."

Ketchum residents Michael and Leslie Engl suggested the Idaho Rockies as material for his canvas after they saw his work at an exhibition in San Francisco. And that began a long-running acquaintance of Foster with the Sun Valley area as he journeyed here regularly to hike to places like Alice Lake with the assistance of Bill and Annie Vanderbilt and others.

Sun Valley Center for the Arts sent Foster down the Salmon River several years ago to record his impressions for a project exploring questions about wilderness preservation and change. And Gail Severn Gallery regularly shows his work.

"Traveling into, and living in, the world's wildernesses, recording my experiences, sharing the delight of my discoveries and arguing for the protection of these fragile places has become the theme upon which all of my projects have been based," says Foster, an amiable man with a white mustache, long straight nose and prominent ears.

One of Foster's trademarks is the mementos - pebbles, map pieces, pieces of wallpaper from abandoned cabins - that he puts at the bottom of his paintings, along with brief "I was there" descriptions. His watercolor diaries expand on his condensed versions:

"Spurred on by the promise of fresh water at Copper Canyon, we arrive at 3.30 to find it bone dry. We are now in trouble ... Find a tiny pothole full of dead centipedes and filthy green sludge. Farther down only wet sand which, when scooped up, smells terrible ... Filter the water twice through my shirt and then double dose it with iodine ... Boil up the pond slime and mix it with porridge and tea. It tastes okay, though still khaki-green."

Foster is loathe to include any evidence of man in what he calls his "iconic subjects of the world."

"I want to inspire people, to show them what is out there in our natural world, to show them what extraordinary things there are to see," he says. "These open places are precious and rare and they need preserving. And, perhaps, my art can be seen as another small argument towards saving some of the precious places we have in our world."