Ever since Matthew McConaughey signed on to star in Born to Run, there was one key detail missing: Which character would he play?

Deb Newmyer, president of Outlaw Productions and one of the film’s producers, told Runner’s World Newswire that McConaughey will play the role of Caballo Blanco, a.k.a Micah True, the ultrarunner who often ran with the Tarahumara people in Mexico. He became a central character in Christopher McDougall's book Born to Run and later died on a run in New Mexico in 2012.

“As I understand, Matthew read the book and fell in love with the character,” says Newmyer. She added that they also might film on location in Copper Canyon in Mexico, but that no specifics have been set.

Caballo Blanco—translated to “white horse” in English—is an eccentric character, which seems to fit with the roles McConaughey has excelled at in recent gigs like Magic Mike, Mud, the HBO series True Detective, and Dallas Buyers Club, which he won as Oscar for last year.

Originally Peter Sarsgaard was to set to write and direct the film adaptation and, when Sarsgaard’s brother-in-law Jake Gyllenhaal discussed his interest in barefoot running on the Late Show with David Letterman in 2010, rumors started flying that Gyllenhaal would star in the film.

In 2013, however, McDougall told Competitor.com that Sarsgaard’s interpretation of the story “just wasn’t flying.” McDougall is listed as a writer on the film, though the degree of his involvement is unclear. “I anticipate he will be on set,” Newmyer says. “We adore him and want to capture his voice as part of the process.” McDougall did not respond to multiple interview requests.

McConaughey is the only actor who has signed onto Born to Run at this stage. His IMDB.com page shows he’s currently filming two movies and has another two in preproduction, indicating the movie is likely still years away.

Any runner with Hollywood aspirations may also be interested in possibly being in the film. The Born to Run film adaptation will showcase the Leadville Trail 100 and the 50-mile pursuit across the Tarahumara country and needs help filling out the fields.

“We will be looking for runners,” says Newmyer. “We won’t CGI them in.”

Newmyer, who has been producing movies for more than 30 years, is a runner who puts in two miles on the treadmill three times a week. She was attracted to the story because it has “so many exotic, eccentric, driven human beings that I rarely encounter,” she says. “I wanted the world to get to meet them all.”