Idealism can be contagious. In 1950, a group of 47 Alabama Quakers set out for Costa Rica to save themselves. The conservation ideas they subsequently developed, coupled with Costa Ricans' pride in their environment, may now help save the world.

A pilgrim's odyssey to a better life is a story as old as America itself, of course. What's unexpected is to meet a real-life pilgrim in a tropical cloud forest. Waiting for us at a trailhead is Wilford "Wolf" Guindon, a 71-year-old member of that original migratory group equipped with steel-wool sideburns, an impish wit, and a walking stick as sturdy as his legs.

Early in his half-century here, he introduced his new neighbors to the efficiencies of the chainsaw. More recently, he proudly designed completion of a new trail in the Monteverde Cloud Forest Preserve that didn't disturb a single tree.

His evolution from jungle-clearing pioneer to ardent conservationist is typical of the surrounding community, which has discovered that preservation pays. Monteverde markets the natural world. The new trail climbs as steadily as Wolf does, leading our One World Journeys' expedition group toward the continental divide and a view of the silver Pacific, at least twenty-five miles away.

"Typical me, I want to see something on a trail," Wolf explains. "If you want to name a trail after me (the Preserve did), you have to make it go the hardest way."

None of us are complaining. The magic of Monteverde has us entranced.

We've come to see a spectacular ecosystem endangered by global warming. Our group's center of gravity is photographer Gary Braasch, of Portland, OR, who for three years has been compiling a visual record of climate change, from the Arctic to the equator. He convinced One World Journeys to come to the cloud forest to examine evidence of a warming world.

Our leader is Denise Rocco, a Bay Area professional photographer and veteran of several owj.com expeditions. Her constant sidekick with headphones and microphone is fellow Californian Toby Malina, the computer whiz responsible for getting these wilderness experiences from the field to the Internet.

The scribes of the group are my wife Holly, a teacher and a writer, and myself, a journalist and author, both from Anacortes, WA.

Jason Roberts, a biologist and computer expert who worked in the Preserve for a year, has traveled from Washington, D.C., to make introductions to scientists and to interpret.

Our initial drive to Monteverde was on a precipitous, potholed dirt road that climbs dizzying ridges. It doesn't flatten when the community is reached: the pastel houses and tourist hotels cling to the steep muddy drives with limpet tenacity, scattered among the trees as if cast like dice. The community is rambling, alternately rustic and swank, and fast-changing.

Trade wind clouds hurtle across the mountaintops so quickly that Toby compares their rush to time-lapse photography. Sheets of fine rain come and go, hanging against the forest like a dancer's veil and then teased away. Vine roots hang like ropes.

We've been awed not just by rainbows but a moonbow, a milky crescent cast by the full moon, that faintly displays the same spectrum of colors as those in a sun-cast rainbow. Equally stunning is the Resplendent Quetzal, the proud male bird puffing out a ruby chest and flaunting iridescent green tail feathers like a king's robe.

Wolf points out a slithering brown snake, a parade of leaf-cutter ants, a writhing millipede, and a pouting scarlet flower he calls "hot lips."

"Every fifty yards has some memory for me," he says. Here, a cow became trapped in a ditch, and the farmers came for meat; there he shot an armadillo that tumbled over an edge. When his Quakers arrived at Monteverde the only way in was an ox-cart trail, and electricity was years away. Now there are Internet cafes nearby, no hunting, and disturbing signs of climate change: higher clouds, less rain, and lower rivers.

Before arrival, Wolf served several months in prison for refusing the U.S. military draft at the beginning of the Cold War. "We believe that God is in every individual, so the taking of human life is absolutely forbidden." In 1950 he and his neighbors in Fairhope, Alabama, decided to immigrate to a country that had just abolished its own army after a bloody civil war. Costa Rica welcomed them.

The Quaker agreement to preserve their forested watershed in Monteverde was the nucleus of the cloud forest preserve. Their presence drew scientists whose ecological work spurred on conservationists, who in turn enlisted the support of local Costa Ricans. "People realized there were more jobs from preserving the rain forest," Wolf says from a spectacular new bridge that takes hikers across a ravine and through the forest canopy. "I had people show me the knives in their boots when we first wanted to buy the in-holdings and then later invite me into their homes."

Monteverde became not just a center of environmental research but an experiment to save tropical rainforests from development pressure. Since Wolf's arrival, Costa Rica's population has quadrupled and yet 27 percent of its land is in some kind of reserve.

Setting aside land is one thing; however, living on it sustainably is another. Land prices have soared in Monteverde and tourism has produced regret as well as opportunity. Down in the breathtaking beauty of the San Luis River Valley, 24 Costa Rican families are trying to demonstrate an alternative future. We descend to take a look.

Their land used to be windblown pasture, the cloud forest cut for cattle. In 1993, American Quaker Ann Kriebel joined with the natives to acquire 50 hectares, or about 125 acres, and turn pasture into intensely planted subsistence farms.

Resulting life in Finca La Bella is lovely and hard. Most homes were built from scratch, and cash crops -- such as coffee, bananas, and sugar -- typically earn each family only $1,200 a year. Nearly all the men hold second jobs, and families grow vegetables and raise chickens and goats for food. Most have only an elementary school education, and until recent acquisition of a trail motorcycle, farmer Marcos Marin hiked several miles up a steep mountain road each day to his maintenance job. Because he can't afford to send his children to high school, his twins tend their own garden plot in hopes of selling enough produce to afford required uniforms and books.

Yet in less than a decade the farmers have transformed the landscape with windbreaks of native trees, colonizing forest, flowers, and a mix of crops that attract bird life and provide wildlife corridors. They deliberately don't own cows or horses that would compact the soil. They've cut pesticide use by 80 percent and create compost, all to save their world.

"This forest belongs to everyone," Marcos says, pointing to the ridges above.

The Dutch gave money for a nursery and the Danes ordered avocado seedlings for a greenhouse, explained project leader Oldemar Salazar. Surplus plants are planted at Finca La Bella. The group has also started a preschool and a health clinic. "The doctor only comes once a week, and so we only get sick on Mondays," Salazar joked.

Yet success is not assured. A nearby communal farm collapsed and financial aid to this one has dried up. These farmers, averaging just five acres each, compete with industrial agribusiness.

Their pride and love for their land is unmistakable. Salazar picks sweet lemons for us - they taste like a tart orange - and then leads us to Marin's farm to plant trees. The forest above riffles in the breeze, birds flit through the windbreaks, and the sun dances at the same time that puffs of fine mist tingle our skin. The farm seems an idyll of an earlier, simpler time.

It is Marcos' daughter Neiby, age seven, who plants the last avocado, a favorite food of the Quetzal. We say adios to her with tentative hope. Girl and tree seem a promise for the future.

(Donations toward the Finca La Bella experiment in sustainable agriculture can be sent in care of Oldemar Salazar, Asociacion Agricola, Finca La Bella, Monteverde Puntarenas, Costa Rica.)