Like many people on vacation this summer, Mike Towne's daily responsibilities were pretty simple.

"You just have to wake up and go north," he says. "You walk and sleep; that's all you have to worry about."

And food and water. And bears. And his poor, aching feet.

Above all, Towne's summer was all about heading north, as he covered 2,650 miles on the Pacific Crest Trail between Mexico and Canada.

Towne, 27, lives in Carmichael, Calif., where he has been a civil engineer. But between April 21 and Sept. 4, he was a citizen of the crest, a man of the mountains.

"I'd say I started thinking about doing it about a year before I actually did," he says. "It just hit me one day: 'I don't really want to be at work, so I think I'll go do this hike.'"

Undertaking the Pacific Crest Trail isn't just "doing a hike." It's often difficult, sometimes uncomfortable, occasionally dangerous and, above all, a very, very long haul.

It winds through some of the most beautiful and diverse scenery in the world, beginning in the Southern California desert for a couple hundred miles, then climbing among some of the country's tallest peaks in the Sierra, through rain forests in the Oregon Cascades and all the way through Washington to Canada.

According to the Pacific Crest Trail Association, about 300 people a year set out to hike the entire trail. About 50 to 100 a year finish the whole thing, according to Angela Ballard of the association.

There is, according to Towne, a very particular culture around the undertaking, some unique challenges, and a lot of things to learn about day-to-day survival. There's much to think about before heading out, he says.

There is the choice whether to hike alone or with someone, weight considerations, coordination with care packages from home, technology for keeping in touch with friends and other aspects to be thought through.

And it's not cheap: Towne says most people figure on spending a dollar a mile, but he spent more, nearly $4,000.

And there are other surprises, not all of them water-borne parasites (Towne caught two) or rattlesnakes (he encountered more than a dozen). Some of the best surprises he discovered were the people, particularly in the southern desert, who went out of their way to help those who undertake the trip.

"There are people who take you into their home," he says. "We call them Trail Angels. There's one lady in Agua Dulce, near Lancaster, who has tents in the backyard, an RV, Internet, a phone you can use, and she'll even feed you a dinner. You usually give 'em a $20 donation. There are five or six of these."

Then there are the people, some locals, some former hikers, who want to help by leaving water caches in established places, usually near road crossings.