Rapid City S.D. ? Forty years after becoming the only American to win Olympic gold in the 10,000-meter run, Billy Mills is just getting back on his feet after a rare ailment forced him to the sidelines.

In 1964, he surged past two favorites in the Tokyo games to set a record — a win that Runner’s World Magazine calls the “best out-of-nowhere performance.”

A Lakota Sioux who grew up on the Pine Ridge Indian Reservation and was orphaned at 12, Mills was the subject of the 1983 movie, “Running Brave.” He ran in college at Kansas University, and today he lives in Sacramento, Calif., and gives motivational speeches about 300 days a year.

Looking much younger than his 65 years, Mills still flashes a wide grin. But because of a malady diagnosed a year ago, he only recently started feeling healthy again.

While competing in the Southwest in the early 1970s, he contracted a little-known and noncontagious disease found in that region — coccidioidomycosis, or valley fever. It is caused by fungal spores kicked up from the ground. Although usually not serious, the disease, which has flu-like symptoms, can lead to meningitis and joint pain. It had forced Mills to all but give up running because of excruciating pain.

“I didn’t want to tell anyone that my joints were just painful, because you’re the Olympian. You don’t want to say that,” Mills said.

Since his diagnosis, he has been on a medication that has killed off the disease and restored his body to some degree of pain-free flexibility. He’ll stay on the drug for another year or two to make sure it doesn’t reappear.

Mills’ main limits now are imposed by knee injuries suffered while skiing, something he attributes to valley fever because it threw off his balance.

He said he’s feeling better, but his athletic goals don’t include running. He wants to make strides in his golf game by breaking 80 — something proving more stressful than any pre-race jitters.

Former Kansas University track standout Billy Mills poses for a portrait in this February file photo.

Mills and his wife, Pat, plan to attend the Summer Olympics in Athens, the birth of the games. And he’ll likely carry the torch part way, which he has done since 1984.

Asked about his October 1964 victory, Mills offers no lively quotes about athleticism or the will to win. His message, when he gives talks, is about having the passion to pursue your natural ability.

Mills said the same principles of responsibility and character that helped him win the gold were the same ideals that could help business leaders and their companies thrive and avoid legal, moral and ethical trouble.

During his running career, Mills had to overcome racism from American Indians because he was part-white and prejudice from whites because he was a Sioux. Hate, anger, self-pity and jealousy will destroy a person, he said, so he had to look deep within himself to succeed.

“That’s where the dreams lie. You’ve got to dig so deep through all those emotions to find the dreams. You get to know yourself. You find the passion. You’re self-motivated,” Mills said.

Billy Mills holds off Mohamed Gamoudi of Tunisia in the 10,000-meter race at the 1964 Tokyo Olympics, a race he won.

When he broke the tape to win the 10,000, he recalled lessons his father taught that were based on Greek philosophy and native spirtuality.

“I realized, ‘Wow, I didn’t win this race.’ I found the passion. I pursued it with all the intensity possible but with a vision and a mission statement that was value-based and I kept it sacred,” Mills said.

“This moment in time for me was God-given. I didn’t achieve it. I did all the work for it but it was God-given. That’s the most humbling experience you can ever encounter.”