Simon Donato, right, and Keith Slzater, left, meet in Calgary before leaving for their search. (CBC)

A Calgary geologist has taken a leave of absence from his job to lead a team that will try to find the remains of U.S. adventurer Steve Fossett.

Fossett, who set a record for flying solo around the world in a balloon, disappeared while on a routine flight in Nevada in September 2007. His disappearance sparked the biggest search in U.S. history, covering nearly 52,000 square kilometres, but no clues were found.

Calgary geologist Simon Donato believes searchers were looking in the wrong place, and that millionaire's plane went down in a forested area missed by an air search.

"I've flown the area myself to get a sense of the terrain, looked at their search maps, and then from that, synthesized all the information and decided to focus on the margins of the search area and the margins just so happen to be the Sierra Nevada mountains," he told CBC News Tuesday.

Steve Fossett emerges from the GlobalFlyer in 2005 after flying solo around the world without refuelling. (Charlie Riedel/Associated Press)

Starting on Monday, Donato and a group of eight endurance athletes will search an area southeast of Lake Tahoe on foot for eight days, covering up to 40 kilometres each day.

"We're going to focus on these heavily wooded areas and just move through as quickly as we can in whatever kind of search grid we'll select for the particular area," he said.

Officials in Nevada are skeptical: "I wish them all the luck in the world. I think they've got their work cut out for them," said Joe Sanford, undersheriff of Lyon County, Nev.

Fossett's family, who successfully argued for the adventurer to be declared legally dead earlier this year, have so far ignored Donato's calls and e-mails.

But Donato doesn't see that as a sign to stay away. The California-born Fossett completed Alaska's Iditarod sled-dog race, scaled some of the world's famous peaks, and set dozens of aviation and distance records.

"Steve Fossett is an inspirational guy. I mean, he's lived an amazing life. He's done all of these adventures and he's explored, he's challenged himself, and he's pushed others to challenge themselves too," said Donato.

Calgary Search and Rescue volunteer Keith Slzater was doubtful at first but has since joined the group as base camp commander.

"I've seen the effort that Simon's put in, and zeroing down, and using very, very good techniques to zero down a search area," he said. "And it was just one day I sat back and went holy cow, our odds are going up."

The group, which is covering its own expenses, will document the search on its website.