At 75, Willie Nelson tours 200 days of the year, smokes weed nonstop and is trying to launch a biodiesel revolution. On the bus with the world's mellowest man. 

IN THE 100-DEGREE HEAT OF A TEXAS AFTERNOON, HUNDREDS OF WILLIE Nelson fans make a pilgrimage to see their prophet, priest and king, in a particularly unassuming spot -- Carl's Corner, an interstate truck stop on a dusty plateau between Austin and Dallas. The stop, and the town to which it belongs (pop. 134), is presided over by Carl himself, a wheezy, unkempt Santa Claus with nine fingers -- a rattlesnake has the 10th -- and a knack for schemes to separate truckers from dollars. He tried a swimming pool, 24-hour restaurant, wedding chapel and strip club before turning to his good friend Willie Nelson, who had a notion that might work -- and also help to save the planet: a biodiesel station. Two years and several million dollars later, a large stainless-steel plant run by Pacific Biodiesel rises mightily behind a new wood-paneled juke joint, to supply the 14 gleaming pumps in front with 8,000 gallons of biodiesel per day. The stop is now named Willie's Place. 

In the typical Willie way, the scene is chaotic at today's 10 hours of concerts by Willie and friends -- including Ray Price, Johnny Bush and David Allan Coe -- with cowboys patting pockets for drink tickets and bum-rushing a buffet supper. Yellow caution tape has been run around all the pumps, which, it turns out, aren't yet hooked up to biodiesel. "Oh, they'll get around to putting it in those pumps for folks eventually," says Willie, grinning a bit. Though his face is deeply creased, his brown eyes a little cloudy and his beard and eyebrows completely white, the cosmic cowboy-Buddhist is dressed today like a kid at play: black T-shirt with the sleeves cut off, worn black slacks and gray New Balance sneakers. Age has made him even mellower than he used to be, say bandmates. He's become almost pathologically attached to surrounding himself with positive vibes, but there's a hitch: Willie likes to stir up trouble. In fact, the more things that go wrong, the happier he is. 

"A lot of Willie's life operates on the chaos theory, which doesn't often happen in entertainment -- or happen artfully in entertainment," says Joe Nick Patoski, author of Willie Nelson: An Epic Life, a biography of Willie. "He's a lot more complex a person than people give him credit for, and it's a complex world around him. But he's been very good about sailing above it all by sticking to what he does." 

What he does, first and foremost, is work. Willie, who has sold more than 50 million albums in his lifetime, has been busy with many projects this year: In addition to lending his support to causes like Myanmar relief, he has kept up his long-term work with Farm Aid and equine-rescue outfit Habitat for Horses; a collaboration with Wynton Marsalis; a co-authored Western novel; as well as an appearance in the 2008 Toby Keith film Beer for My Horses, a cameo in Snoop Dogg's song "My Medicine" and a new song for an upcoming film, Tennessee, with Mariah Carey. In February, he is releasing an album of Western swing songs with Asleep at the Wheel. In fact, he'd like to rerecord a lot of his own work. "There's songs that I've had, good songs, that never got their due," he says, nodding his head firmly. In March, Naked Willie, an album of Willie's recordings on RCA from 1966 to 1970, without the strings and schmaltz, produced by his harmonica player, Mickey Raphael, will be released. "For the album cover," says Raphael, "Willie took a picture of himself with his iPhone while he was in the bubble bath, and sent it to me." 

Yes, Willie has an iPhone. 

The hardest work of all -- or the most fun -- is touring. At 75, Willie travels about 200 days a year with the "Family Band," a group that includes his 77-year-old sister, Bobbie, a pianist. Though he gets the occasional bout of heatstroke, he tries to stay in shape on the road: He bikes, practices yoga and bowls on his Wii with his teenage sons, Lukas and Micah, a guitarist and a percussionist who tour with him in the summer. 

"I've heard that lots of senior-citizens centers are getting Wiis, because it really does work," Willie says, eyes glittering with excitement. He leans in. "You know, most 75-year-olds already decided to hang it up a long time ago. I would never be in that mind-set, because I enjoy what I'm doing. As long as I'm healthy, I'll never leave the road -- well, if people stopped showing up, that might be a reason to quit it. But I'm watching people like B.B. King, or Ernest Tubb, who toured until he died. I'm not ready to quit." He juts his chin forward. "I'm not ready to die, either." 

We're talking on Willie's bus. Where else would we be? He rarely leaves it, unless he needs to go onstage: It's his "submarine," as he has called it, a darkly tinted bubble from which he watches the world drift by or invites it in. When he's at home on his ranch in Austin and his wife, Annie, isn't in town -- she has made their other home, in Maui, Hawaii, her primary residence, an arrangement that suits both of them fine -- he prefers to sleep on the bus, the rear end of which has a psychedelic portrait of his face morphing into an eagle. The bus is spick-and-span throughout, with black leather seats and mahogany builtins, and a few personal touches: photos of his grandkids tacked on a corkboard, bumper stickers like MAKE LEVEES, NOT WAR on the fridge. His daughter Lana, 55, makes eggs for her father at midnight as they roll in to a new town, and he takes naps a couple of times a day back in his bunk. 

"These days, I don't have many dreams," Willie says. "That's a side effect of smoking pot -- a bad one, or a good one, depending on what your dreams are." Another side effect: saying yes to almost everything. "He's high, so everything sounds good to him," says Raphael. If something sounds bad, he tries to forget that he heard it. "Willie never lies," adds drummer Paul English, whose first job was playing with Willie in 1956 (he swears it will be his last one, too). "If I ask him something and he doesn't answer, I never bring it up again. That's his way of saying no." 

The kitchen nook is where Willie receives friends, with XM classic country on the dial and his favorite things on the countertop. Not only does he have an iPhone, but he's brought along two Mac PowerBooks, to check e-mail and surf the Net for left-leaning conspiracy theories (he is not sure that 9/11 wasn't an inside job). Each of the computers has long, heavy scratches in the titanium, because fellow travelers have been known to throw them when experiencing technical difficulties. The real test of a star musician's character is the cohesiveness of his band, and Willie has kept them close -- he's fired only two members in 30 years. He's become more involved with his biological family as well, committed to maintaining a tight unit with his current wife and teenage sons. "Every morning, Willie looks in the mirror and says, 'Open your heart and give love a chance,'" says Turk Pipkin, an old friend and coauthor of The Tao of Willie. "It's nothing that he's shy about, and it's served him well." In return, those around him give him fealty and protection on the road -- they know the best medicine for his advancing age is music. "Willie has so much creativity, and it hurts to hold it in," says Raphael. 

This may be the case, but Willie can also be difficult. His Texan instinct to trust the most outlandish huckster in the room is problematic: The original biodiesel company that Willie backed is flailing, its stock price trading for less than a penny these days; at today's concert, he's promoting a Wataire machine, a kind of glorified dehumidifier that creates purified drinking water and has a price tag of $1,600. And he himself is covering up many scars -- no account parents who split quickly after his birth, leaving him to be raised by his grandparents in Depression-era Texas; the years he spent in Nashville as a struggling songwriter in the Sixties, until he finally broke through in the mid-1970s; a debt of $16.7 million to the IRS in the early Nineties, which he paid off partially by auctioning his homes and possessions; three divorces, not always amicable; and the suicide of a son in 1991. "This is a guy who has really seen the dark side, and people don't think that about Willie so much," says Billy Bob Thornton, who is beginning work on a documentary about Willie, and whose band, the Boxmasters, toured with him this fall. "Willie doesn't talk about the torture he's been through. It only shows on his face." 

It's a heady mix for guys looking for a father figure and hoping to hang with one of the world's last pot-smoking icons. Woody Harrelson, Luke and Owen Wilson, and Johnny Knoxville have all become very close to Willie in recent years. When Knoxville appears at a concert the next day, he grabs crew members in big bearhugs. "I thought your granddaughter was a beauty, and then I saw your daughter!" he tells the stage manager. Later, he becomes choked up while talking about Willie. "I'm from Tennessee, and just to meet Willie was an honor for me, but to call him my friend¦" he says, then trails off. "It's an understatement to say it's a special friendship for me." 

Harrelson has become a kind of Boswell for Willie's funniest lines, which he types into his BlackBerry -- "If you're going to have sex with an animal, make sure it's a horse, because then at least you'll have a ride home," for example -- and is a regular at his poker games in Maui. "One time, my wife gave me some money to play poker," says Harrelson. "I said to Willie, Ah, she gave me this money, and I know I should triple it, but instead I'll come home tonight smelling of whiskey, slobbering and broke.' Willie said, 'You have that right! As the breadwinner, it's not only your right -- it's your responsibility! You have the responsibility to be irresponsible!' That was one of the most freeing things I ever heard in my life. I really needed to hear that." 

Today, Willie takes the stage twice in the sweltering heat, sticking to his most popular songs, like "Good Hearted Woman" and "Crazy," rarely cracking a smile until the end, when he lifts his Stetson hat in farewell. As the chaos of mixed-up tickets, high school security guards and a mob of fans rages outside the bus, one of Willie's roadies, Ben Dorcy, climbs on with Ray Price, who has come to sing a few tunes. Neither man is moving particularly quickly: Price is 83, and Dorcy, a former valet for John Wayne who smokes London Fog in his pipe, is 81. Price gives a kiss to Willie's wife, a curly-haired hippie chick who is about half as old as anyone in the room, then turns to "Sister Bobbie," who is drinking coffee out of a china teacup. "Every night, we get our energy from our audiences," she says. "Maybe it's what we put out, but they give it back, and that's the fuel we need to get through the next day." 

Price and Willie sit down at the kitchen nook in front of a big glass ashtray filled with marijuana, for use in Willie's vaporizer, which was gifted to him by a dude Harrelson met on the beach in Maui. "I'll smoke anything that comes around," says Willie. "It doesn't matter to me what type it is. People like to give me it. They feel that I shouldn't be without it. The vaporizer makes it easier on my lungs, because I was coughing and wheezing a lot." Is he worried about getting busted for possession again? "You think I won't?" he says, grinning. 

Willie tells Price a few jokes -- "I've got a new song called 'I Called Her a Bitch, She Called Me a Son of a Bitch, I Think We Might Make It Work This Time,'" he says, laughing -- and starts talking politics. He's excited about President-elect Obama, who he thinks is a "good guy, with good ideas, and a good change," he says. "I never did know if we'd be sharp enough to let the right guy in no matter what color he was," he adds, then cocks his head. "I was talking to my friend Gatewood Gailbraith the other day, and I asked him what he felt about Obama. He goes, 'It's like a turtle on a post. You see it, and you think, "How'd that get there?"'" 

Everyone dies laughing, and Price tells Dorcy to grab a bag of peaches that he bought at a nearby farm stand. Dorcy starts toward the door, inch by inch. 

"Hey, Ben-Ben," Willie hollers. "If you can't find those peaches, just bring us some doughnuts." 

Then he takes a puff on the vaporizer. 

"I'm working on levitating," he says, letting out a stream of smoke. "You'll know when I pass by."