LOS ANGELES — The vacant lot near the corner of Seventh Street and Bellflower Boulevard in Long Beach was perfect for the young Scot Breithaupt.

Amid run-down Quonset huts and maintenance shacks for the nearby oil wells, Breithaupt cut a few dusty trails through the weeds with his bicycle, invited friends over and helped start a craze that in time would transfix the world.

Scot Breithaupt rides in a BMX race in 1976. His death is being investigated after his body was found in a tent in a vacant lot in Indio, Calif. 1976 BMX photo/AP

The renegade races that Breithaupt organized on that dirt lot soon evolved into BMX – bicycle motocross – a sport that draws hundreds of thousands of enthusiasts and, in 2008, debuted in China in the Olympics.

Admired for his skills as a rider, Breithaupt was also a key promoter, co-founding a trade magazine, establishing a professional organization for BMX racers and developing components for the bicycles.

Breithaupt, 57, was found dead in a tent in a vacant lot Saturday evening in Indio, southeast of Palm Springs, authorities said. The Riverside County coroner is investigating the circumstances of his death.

Much as Hobie Alter transformed sailing, surfing and skateboarding in the 1960s, Breithaupt radicalized – and popularized – bicycle riding by borrowing from the off-road skills of motorcyclists.

“He was an entrepreneurial teenage kid, but just always going at 100 miles per hour and super energetic,” said Craig Barrette, a spokesman with the international BMX racing organization, USA BMX. “With his contagious enthusiasm for this new sport called BMX, his races just kind of got bigger and bigger.”

By the age of 12, Breithaupt was racing a Yamaha in motocross competitions, and according to his brother, Jeffrey, was having so much fun that he thought other kids should experience the sport.

But not everyone could afford a motorcycle. Pedal-cross – as Breithaupt first called it – became the alternative, and the Stingray bicycle with smaller wheels than traditional bikes was suited to quick and agile maneuvering. Soon Breithaupt and other Southern Californians were perfecting long wheelies and distance jumping on dirt tracks.

With the natural charisma and energy of a rock ‘n’ roll promoter, Breithaupt took BMX racing onto a national stage.

He was born in Long Beach on July 14, 1957. His mother, Carole Faye Breithaupt, was the first Miss Long Beach in the Miss America pageant in 1950. His father, Leo Breithaupt, was a small-track race car driver, who competed in the California Jalopy Association.

‘ALWAYS TAKING RISKS’

Scot was always taking risks, his brother recalled, riding his bicycle off the roof of the junior high school cafeteria and the top of a house into a swimming pool.

In the 1980s, according to his brother, Scot had become addicted to crack cocaine. He lost control of SE Racing, and in a 2012 posting on the website fatBMX, he described a recent set of problems that included treatment for cancer as well as claims against the state corrections agency.

His brother said that although Scot had been living with his mother in La Quinta, near Indio, he would disappear for days.

“He was a remarkable guy,” Jeffrey Breithaupt said. “Drugs were his torment.”

In addition to his brother, he is survived by two sons, Scot and Brandon Breithaupt; a sister, Lynda Muenzer; and his mother.

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