One hiker's weekend recreation is another fellow's path to opportunity. I encountered this duality in a wooded area called California Gulch near the ghost town of Ruby, Ariz., where I met the first of many trekkers and trailblazers who regularly venture, as I do, far from the main thoroughfares of the Americas.

Friends and I came upon a barbed-wire fence so flimsy and rusted you wouldn't hang laundry on it. A severe drought had dried up arroyos and creeks; the carcasses of cattle lay nearby. I stepped over the twisted fence. "By the way," our leader mentioned in passing, "you just entered Mexico."

"You mean," I said in wonder, "I'm in another country now?" I stepped back over the fence. "And now I'm back in the United States?" The joyful anarchy of stepping from one sovereign nation into another seized me, and I began to jump back and forth over the fallen international boundary like a child jumping rope. The others tired of my antic long before I did, and we soon set up camp nearby.

Later we met a Mexican walking north who had also found the same spot to his liking. For him it was an easily scaled hurdle on his road to livelihood. In conversation, neither of us could adequately put to words the significance of that place. To each, however, the crossing represented the cleansing air of freedom.

To walk where no one has gone before, to be the first human whose shoes break twigs underfoot and see the night sky from a newly christened campground -- that's the stuff of prideful whimsy. You have been anointed a pioneer, and your discovery will be told and retold -- even if only by you. Still, there is something reassuring in the knowledge that someone has preceded you. Confronted with the rare opportunity to explore terrain thus far untrammeled, the thought must occur to the most seasoned solo traveler: Damned if I'm going to be the first person on this trail. Anyone want to come with me?

Camaraderie can be the most important element in a journey. A friend along heightens your power of observation. You share not only food and gear but insight and silence. In Peru I traveled alone to Machu Picchu, and arrived at the last minute for the morning train from Cuzco. A Roman Catholic missionary from Italy, a longtime resident of the area, was escorting 50 local Indians to see "the lost city of the Incas." Their ancestors lived under Inca rule, and they, like the rest of us, were curious to see a center of the empire. Chewing coca leaves, chatting in Quechua and dressed in ponchos, the natives provided stark contrast with the international tourists on board. They had been given a car of their own attached to the rear of the train. It was this car whose steps I leapt upon and whose metal grip I clung to as the train began chugging out of the station.

Immediately the Indians made a seat for me and crowded around. We had two things in common: We were headed for Machu Picchu, and Spanish was the weakest of our three tongues, but the only one we shared. We talked of tourism and crops, of trains and communication. They asked from where and why I came to their land. I wanted to learn what they farmed and about their language. One of them reached into his plastic bag and pulled out a piece of fruit for me. After 20 minutes we reached the point in our conversation where the novelty of it wore off and humor and digression crept in. Just then the conductor passed through. "I'm sorry, sir," he said to me. "You'll have to move to another car." He glanced around. "It's not safe in this one, you know."

The Indians looked at each other quizzically. "I feel perfectly secure here," I replied. "I don't mind staying." My entreaty met firm resistance. "No. This is for the indigenous. There's a seat for you farther up." As the conductor led me from the Indian car, my newly made and lost friends lowered their eyes and renewed their Quechua chatter.

At one point near Machu Picchu the Inca Trail winds narrow and high. No railing protects the hiker from the gorge below. I suddenly felt unsafe and, worse, helpless, and inched myself along the mountainside wall. My fear was induced by the height and my state of mind. I came to know acrophobia.

That veteran traveler's mantra "how do I get out of here?" came to mind. The most nagging and fearful thought briefly visited me: It might be easier to slide into the abyss below than to continue on like this. Just then, four spritely Swiss ladies who appeared to be in their sixties bounded by. Sweaters circled their waists and sneakers covered their feet. Totally oblivious to the dangers that dominated my mind, they joked and laughed with each other, and pranced by as if on a wide sidewalk.

Talking with others who travel the gringo trail, I heard time and again of robust and energetic Swiss women in their sixties who confronted and conquered virtually every natural barrier known to explorers, from white-water rafting to high-altitude ice climbing. It was uncanny -- perhaps the same four travelers had ventured so far and wide and accomplished so much that their activities had taken on legendary proportion. Or perhaps the world is filled with Swiss women in their sixties who shame the rest of us as they log mile after mile of adventuresome pathways. Either way, their presence broke the grip of fear that held me, and I continued along my way.

The most accomplished trailblazers live in the Barranca de Cobre of Chihuahua, Mexico's Copper Canyon region, between Chihuahua and Los Mochis. There, the Tarahumara Indians travel long distances on foot, running all morning, through the afternoon and into the night. What is it that allows this remarkable group the stamina of oxen and the grace of leopards? They run as a practical matter and for recreation.

At the very bottom of one of the canyons lies the village of Batopilas, a small pueblo whose silver lode has long been mined out. Yellow flowers so bright they compete with the sun fill every front yard. The mailman rides through on horseback twice weekly. In the plaza sits a genial man who engages the rare visitor in conversation about authors B. Traven and Gabriel Garci'a Ma'rquez, and whether or not Alaska and Russia were once part of the same land mass.

At nightfall three companions and I piled into a four-wheel-drive vehicle for the arduous journey back to our lodging. The rocky and narrow unpaved road hugged the canyon wall as it curved its way up the barranca. A half-hour outside of town we spotted something moving in our headlights. It was a Tarahumara running barefoot up the steep mountainside. Strapped around his shoulder was a large drum that he beat every few strides. His pace was steady and seemingly effortless.

A fellow passenger who lived in the area called out to him in the Tarahumara tongue as we got closer: Would you like a lift? The running drummer paused to consider the offer, and climbed into the seat next to me. He was not short of breath. He was not even breathing heavily. His thighs and legs appeared as rocks. Had he not been carrying the large drum, he told the American expatriate who lived nearby, he probably would have declined the ride and continued running.

His endurance was mystifying. He seemed neither pleased nor displeased that his evening run home had been replaced by a ride. Five miles up the road he signaled us to stop, and he thanked us and got out. By the time we reached second gear he had disappeared into the mountainside.

To each of these -- the Mexican entering the United States, the Peruvian Indians, the Swiss hikers and the Tarahumara runner -- I hoped the words of Roy Rogers would ring true: "Happy trails to you, until we meet again."

Tom Miller's most recent book is "The Panama Hat Trail: A Journey From South America" (Morrow).