Tracy Burge hopes to mark her 50th birthday by riding a mountain bike 2,745 miles along the Continental Divide.

Burge of Clarksville, plans to finish the Tour Divide adventure cycling race from Banff in Alberta, to Antelope Wells, N.M., in less than a month.

The race is the latest extreme challenge for Burge, who said she started down this path in 1994 when one of her sisters proposed that all three sisters run a marathon together.

Since then, she has finished marathons, triathlons and adventure-cycling races. She has ridden the length of Japan, across Thailand and from Athens, Greece, to Madrid, Spain.

“I guess I’m just in search. How far can I go? What’s going to stop me?” said Burge, an environmental education teacher in Loveland.

She would be the first 50-year-old woman to finish, according race organizers and the Adventure Cycling Association.

“I don’t believe a woman that old has done it,” said Mike McCoy, author of the guidebook mapping the Great Divide Mountain Bike Route and writer for the Adventure Cycling Association.

Burge and Sara Dallman, 41, of Lebanon, plan to depart Banff on June 15, the race’s official start date.

Other competitors will start later, including Matthew Lee, known for crossing the route in 15-17 days.

Fewer than 30 cyclists a year finished the race until a documentary, “Conquer the Divide,” sparked interest in the route. Then, 100 cyclists signed up for the 2011 race.

“It was never intended to be a race course,” said McCoy, who rode a Jeep for 75 percent of the mapping.

While confident, Burge is aware that most fail to cross the finish line near Mexico.

“They say most people don’t make it through Montana,” she said.

Contact this reporter at (937) 225-2261 or lbudd@Dayton DailyNews.com.