As the Great Depression hit, work in Cincinnati was getting hard to find and by 1931 Slye picked up and headed to California. Like so many others, Leonard Slye thought he’d find better times in the fertile fields of California. He worked for a while driving a gravel truck and then found work picking fruit for the DelMonte Company in California's Central Valley.
On a lark, he entered a singing contest on a Los Angeles radio show called Midnight Frolics. A few days after his appearance on the radio he got an invitation to join a group called the Rocky Mountaineers. Slye played guitar, sang and yodeled for the group. The group had some minor gigs but wasn’t having much success. After a while they determined they needed to expand their vocal abilities and added a bass player and singer from New Brunswick, Canada by the name of Bob Nolan. Nolan had been working in the bars and clubs of Tucson, Arizona before moving to the Los Angeles area and working as a lifeguard. After a few months Nolan left the band, upset with the lack of any success. He was replaced with Tim Spencer, a worker at the local Safeway warehouse who had migrated from Webb City, Missouri.
By 1933 Leonard Slye was also feeling that the Rocky Mountaineers were going nowhere. He convinced Spencer to quit the band with him and looked up Nolan, who was working as a caddie at a golf course in Bel Air. The three formed a new group, calling themselves the Pioneer Trio. Their combination of close harmony, yodeling, and good, spirited songs won them a job on KFWB radio. To fill out their sound the trio added a fiddler from Plano, Texas by the name of Hugh Farr. KFWB was getting so much fan mail for the Pioneers that they gave them their own show. The show was recorded and replayed across the country on affiliated radio stations. During one of the early broadcasts the announcer introduced them as the “Sons of the Pioneers” claiming that they were too young to have been pioneers. The name stuck and the band quickly gained a large following nationwide.
The band went through a few more personnel changes and started playing to a new venue. They provided the musical soundtrack for the Oswald the Rabbit cartoon that was played in theaters before the headline movie. The next move was to play for full leangth feature films including Gene Autry’s The Old Corral at Republic. In 1938 Autry had a dispute with the studio and refused to show up for the filming. Leonard Slye auditioned for and won the lead part in the cheesy western entitled Under Western Stars. Of course Leonard Slye wasn’t a memorable name for a cowboy hero, so Slye starred in the movie under his new screen name: Roy Rogers.