Ralph Plaisted, who died Monday at 80, left his St. Paul, Minn., insurance agency in 1968 to become the first person indisputably to trek overland to the North Pole. But somehow, his name never quite made the Arctic explorers’ pantheon with Peary and Cook and Byrd, whose achievements were far less certain.

Leading a four-snowmobile caravan, Plaisted succeeded where he’d failed the year before and traveled for 43 days over perilous pack ice to reach the pole on April 19, 1968. A twin-engine Otter then flew them home.

Plaisted later told an interviewer he realized the magnitude of his accomplishment when he radioed the pilot to land at a spot two miles south of the pole.

“Every direction from where you are is south,” the pilot replied.

Born in Bruno, Minn., Plaisted served in the Navy during World War II and in 1949 opened the Ralph Plaisted Insurance Agency in St. Paul. An avid outdoorsman and hunter, he got involved with snowmobiles in the early 1960s and set endurance riding records. It was while he was planning an expedition to hunt seals in the northern reaches of Canada that a friend, Art Aufderheide, a pathology professor and an internationally-known mummy expert, challenged Plaisted to ride all the way to the North Pole. (Some accounts hold that it was Aufderheide’s expedition and that Plaisted suggested skimobiles instead of dogs.)

Commander Robert Peary’s claim to have reached the pole in 1909 had been mired in controversy and was based solely on his diaries. Others claimed to have reached the pole, too, including Dr. Frederick Cook, in 1908, also by sled. Several others claimed submarine and air overflights, and there were a handful of unconfirmed claims by Soviet researchers.

Plaisted spent several years planning his expedition and secured permission from the Canadian government to create a forward base at Ward Hunt Island, 474 miles from the North Pole as the snowball flies. The actual trek over ice, avoiding open water and negotiating pressure ridges, stretched over 800 miles. Sponsorships were arranged from Knorr (soup), Pillsbury (dried meals), and Coleman (tents). The 16-horsepower, single-piston Ski-Doo snowmobiles were the best available in the day. Donated by the manufacturer, Bombardier, Inc., they were specially modified with golf cleats for traction and extra fuel tanks for distance.

Plaisted’s first attempt, launched in 1967 with CBS newsman Charles Kuralt among its members, failed when it stretched too far into the spring and open water made progress treacherous. Plaisted returned in 1968, earlier in the season and with a more streamlined team. Four snowmobiles set out on March 7 from Ward Hunt Island. Plaisted’s lead Ski-Doo was dubbed the Caribou Queen, named for an Inuit stripper he’d seen in Yellowknife. Temperatures from 30 to – 60 degrees Celsius made the trip cold even by the standards of Northern Minnesota. The drivers dodged cracks in the ice and huddled together at night for warmth. They lost weight even while eating 6,000 calories a day.

“Once, we waited for two days for a three-kilometer-wide stretch of open water to freeze enough for crossing,” an expedition member wrote in 1969. “We advanced when the ice was a mere five centimeters thick and jumped our Ski-Doos and sleds over the final meter of open water.”

They marked their progress by sextant. On April 19 they planted the flags of Canada and America on the top of the world. A day later, their position confirmed, they loaded their gear and three of the Ski-Doos onto the Twin Otter and flew back to base. News of the feat flashed around the world, but most called it the second trek to the pole. Subsequent investigations of Peary’s notes cast further doubt on his veracity, but Peary’s version of events received support from his strongest supporter, the National Geographic Society. A year after Plaisted, an expedition headed by Wally Herbert, a National Geographic writer, became the first verified dogsledder to reach the North Pole.

After returning from the pole, Plaisted attempted to organize a snowmobile assault on the South Pole. In 1975, he took his family to live for a year in a remote part of Saskatchewan. He then returned to the insurance business, but maintained a fly-in Saskatchewan fishing camp and used the engine of a snowmobile to power a small lumber mill to build a cabin.

Plaisted felt some bitterness toward National Geographic for not recognizing his feat as the first verified surface trek to the North Pole, though the “Guinness Book of World Records” and others did.

“National Geographic said to me at the time ‘No insurance man from Minnesota is going to make it to the North Pole with a bunch of old cronies,” he told the St. Paul Pioneer Press in 1993.

Earlier this year, he told the Edmonton Journal, “I don’t care. Earlier I did. At this stage of my life, it doesn’t matter so much.”