They met on the Pacific Crest Trail, and by the time they completed the trek from Mexico to Canada, they were a couple.
Adam Bridges and Brittney Yolo of Occidental found a mutual love in hiking that didn't stop with the five-month, 2,660-plus-mile journey through California desert, over the heights of the Sierra Nevada and into the Cascade mountain ranges of Oregon and Washington.
After their first adventure five years ago, they then took on and completed the Appalachian Trail in 2010, a 2,200-mile route from Georgia to Maine.
And in late August, they topped it off by completing an approximately 3,100-mile walkabout on the Continental Divide Trail, from New Mexico over the peaks of the Rocky Mountains and through Montana.
Bridges, 30, and Yolo, 31, are now members of a relatively rarified "triple crown" club of about 200 people who have hiked the length of all three trails.
And they've taken another big step.
"I proposed to her on the Continental Divide," Bridges said last week. "We're engaged."
"He carried the ring the whole way," Yolo added. He popped the question in August, near the end of their hike at a spectacular pass in Glacier Park, Mont., amid cathedral cliffs and shimmering lakes.
Earlier this month the couple returned to their Coleman Valley Road home. They caretake property and have seasonal jobs.
Bridges is employed at Martinelli Winery, putting in long days during the crush as a grape press operator. Yolo works for the Sonoma County Agricultural Commissioner's office as a trapper of the European Grapevine moth.
Yolo had never done any hiking when she met Bridges in a group they were part of on the Pacific Crest Trail.
The Analy High School graduate had a strong athletic background, including a softball scholarship to University of Nebraska.
Bridges, who grew up in Maine an Florida, had already done a lot of backpacking with the ultralight gear they favor.
They share a passion for hiking, but express the appeal of it differently.
"I like to say I'm a hike-a-holic. It's sort of an addiction to me," Bridges says of the feeling of accomplishment that comes at the end of a 30-mile day, or when the whole trek is complete.
"Basically it comes down to the challenge, setting a goal and accomplishing it. I like to do it over and over again," he said.
Yolo emphasizes the simplicity of the wilderness experience.
"You completely remove yourself from what you're doing now. You go back to the basics — water, food and shelter. Everything else is out the door," she said.
"It gives you — I don't know — a meaning to life or understanding of life. You travel so far, go through seasons, mountains, snows and the rains. I feel like I'm prepared for any experience."
Bathing in streams, seeing wildlife, exploring different towns along the trails are part of it all.
"You see things and have been a part of things you never would see in daily life: bears, wolves, weird deer, coyotes and bobcats, snakes and scorpions and beetles and bugs," she said, adding that none were scary or menacing.
Like other long distance hikers, they speak of the "trail angels" they met and "trail magic" that happens.