They keep coming.

Thirty years after legendary author, conservationist and wilderness advocate Sigurd Olson died while snowshoeing near his Ely home, some 500 souls a year make a pilgrimage north to visit Olson's one-room log cabin and rocky, pine-studded "Listening Point" retreat on Burntside Lake near Ely.

Many come because, like Douglas Wood, they are touched by Olson's writings. When he first heard Olson's words decades ago, tears came to his eyes, and his life changed.

"There was an immediate, deep connection I felt," said Wood, who eventually quit his job as a music teacher and became a successful writer himself.

Wood, 60, of St. Cloud, is among a throng of devoted advocates trying to keep Olson's legacy -- and message -- alive. He chairs the board of directors of the Listening Point Foundation, a nonprofit group that now owns and operates Olson's treasured lakeshore property. The cabin, on a 27-acre rocky point, was donated by Olson's family in 1998 and is on the National Register of Historic Places.

"People go to the wilderness for many things, but the greatest of these is the goodness of their souls," Olson wrote.

"His message is all of us need the wilderness for our own spiritual, psychological and physiological well-being," said Alanna Dore of Ely, executive director of the foundation. "He felt those who experienced the wilderness would want to protect and save it."

Said Olson in 1965: "Unless we can preserve places where the endless spiritual needs of man can be fulfilled and nourished, we will destroy our culture and ourselves."

His message remains relevant today, Dore and Wood say. People born after Olson's death are among those trekking to Listening Point. And though his name isn't in the forefront any longer, his legacy remains in many places, including the pines and waters in the Boundary Waters Canoe Area Wilderness, which he is credited -- or blamed -- for helping establish.

"You'd be hard-pressed to find any single individual who had a greater impact," Wood said. He fought against road-building and motor use in the million-acre wilderness "at great personal cost," he said.

He was vilified by some who opposed the wilderness restrictions and feared they would bring economic doom to the region, and Olson was once hanged in effigy in Ely.

Wood said Olson deserves a place alongside the great American nature writers, including Henry David Thoreau, Aldo Leopold, John Muir and Rachel Carson. "He's right up there," Wood said.

His impact was large not only because he was an eloquent writer but because he was a speaker, lobbyist and the face of a movement, Wood said. He influenced more than just canoe paddlers; he influenced politicians and other writers.

Olson's son, Bob, 86, lives in Hayward, Wis., (a second son, Sigurd Jr., died in 2008) and is pleased with the work of the Listening Point Foundation and the Sigurd Olson Institute at Northland College in Ashland.

His father's influence isn't as widespread now, "but people are still reading him," he said. "Yes, he is still relevant. There are so many people who still respect and value him."

But, said Bob Olson, "times have changed. Preservation [of wilderness] is no longer the keynote; it's management [of wilderness]."

Still, he said that after years of reading and studying his dad's work, he's more impressed than ever.

"He worked his whole life trying to be what he believed in. It was in his heart and soul. He didn't manufacture it. It was a mission."

Doug Smith • dsmith@startribune.com