If anyone has earned the right to retire, it’s Gaylord Nelson. The one-time Wisconsin governor, three-term Democratic Senator and lifelong environmental activist was also a military officer, a key player in civil rights legislation and an outspoken opponent of the Vietnam War.

And if you’ve heard of Earth Day — that was his idea, too.

But even at 87 and after a surgery that has limited his speech, Nelson won’t be slowed down. He still heads to the Wilderness Society five days a week, where he works as a counselor as well as a mentor and inspiration for the next generation of environmental activists.

“I don’t want a day off, I want to keep busy on the issues that I’m concerned with,” Nelson said. “I would rather come to the office and do something on the environment than stay home and clean the damned eaves or some other assignments my wife would give me.”

And according to Bill Christofferson, a Wisconsin-based Democratic consultant who just finished writing a book on Nelson’s life, the former Senator won’t stop working simply because the work he cares about isn’t done.

“He took himself off the payroll a few years ago, but the only difference now is that he leaves home 15 minutes later in the morning. He still brings in the newspaper and turns on the lights,” Christofferson said.

Christofferson’s book, “The Man from Clear Lake,” is a political biography that traces the path of this down-home Wisconsin boy from his Midwest rural roots to the halls of Congress. And along the way, from Okinawa in the Pacific to the Wisconsin’s governor’s mansion, he shows how “Happy” Nelson has never lost his small-town charm.

“In the process of doing this I read a fair number of biographies of other Senators,” Christofferson said. “Some of them are fairly boring and I don’t necessarily think that’s the author’s fault. The thing I hope I conveyed in this book is he’s still kind of unchanged by all that has happened to him … he still has this ‘gee whiz’ quality to him.”

Released this month, just in time for Earth Day, Christofferson has been working on the book on and off for the past 11 years. The deeply researched book also gives an intimate look at the personal life of the former Senator. Nelson and his wife, Carrie Lee, invited Christofferson to stay in their home in Kensington, Md., for days at a time during his many research visits, and Christofferson saw firsthand some of the raucous parties the Nelsons have been known to throw. “They have a knack for putting a really interesting group together,” he said. “They just kind of took me in.”

Christofferson, who served as a political reporter in Wisconsin during Nelson’s years in the Senate, said he first got the idea for the book after Nelson lost his Senate seat in an upset election in 1980.

“In Wisconsin he is a giant,” Christofferson said. “I’m still astonished that during the 20 years it took for me to do this no one else did it.”

Christofferson’s book spends a lot of time tracing how Nelson’s simple idea for a day of environmental activism became his defining accomplishment.

The first Earth Day in 1970 involved an estimated 20 million people and was an event that was seven years in the making, Christofferson explains. Before the environmental movement became popular, Nelson, known in Wisconsin as a conservation governor, was out in front of the issue — a place where he often found himself. In 1962 he was concerned that the state of the environment didn’t register on the radar of national politics, so the then-freshman Senator — who came to Capitol Hill ranking dead last in seniority — decided to go right to the top.

Two weeks after his election, Nelson began lobbying then-President John F. Kennedy to take a conservation tour to thrust the issue onto the political main stage. But while Kennedy made the five-day, 11-state tour in September 1963, the press seemed more interested in international politics and the recently signed Nuclear Test Ban Treaty than in Kennedy’s speeches on the environment.

But Nelson was sure that while the press and the politicians might not have been interested in the environment, the people were. During the next few years, he realized that a grassroots approach would be the way to accomplish his goal. He decided to tap the energy of the student anti-war movement and channel it into environmental action. The original Earth Day was created and coordinated out of Nelson’s Senate office, and support snowballed after he announced his Earth Day plan in 1969.

The movement would grow by leaps and bounds in subsequent years. In 2000, an estimated 500 million people in 167 countries took part in the event.

“Nurturing the new post-Earth Day ethic were environmental reporters, publications, lawyers, and environmental institutes at most major universities — all virtually nonexistent before Earth Day,” writes Christofferson. “The movement ‘wrought profound changes in American life — to its landscape, its institutions, and its people,’ one environmental writer said.”

“A lot of it these days happens automatically,” Christofferson said. “He institutionalized it so you don’t need a Gaylord Nelson or a national office. When April comes around every year there’s groups all around the country who do it on their own.”

One person Nelson influenced during that first Earth Day 34 years ago was his current boss, Wilderness Society President Bill Meadows.

“I date my own involvement with the environmental movement to Earth Day 1970,” said Meadows. “It really captured my attention. It’s nice to now work two doors down from him.”

Nelson, who has worked with the society ever since he lost his Senate re-election bid, “is not just our oldest staff member but the one with the most tenure,” Meadows said. “He had numerous options to do other things, but he chose to stay engaged in the policy issues that he cared about.”

And Nelson said his work since leaving the Senate has made him optimistic for the future. He’s quick to tell a story, which also appears in Christofferson’s book, about one young elementary school girl who amazed him on one of his speaking tours.

“This little third-grader raised her hand and she said, ‘I came home last week and saw my mother’s groceries on the kitchen table and I saw a can of tuna and I picked it up and there was no dolphin on it. So I went and got my mother and we took that can of tuna and turned it in for one with a dolphin on it.’

“I think we could go to that little girl’s father’s weekly club and you could ask them all what dolphin-safe tuna meant and one in 10 might get it,” Nelson said. “The fascinating thing is that here’s a little girl imbued already with an environmental ethic that guides her feelings and will guide her all of her life.

“That’s the thing that has happened as a consequence of Earth Day,” he said.