Cheech & Chong performing Saturday in Las Vegas

The duo are celebrating 40 years since the release of their stoner-comedy movie, “Up in Smoke,” and 10 years since their onstage reunion at The Comedy Festival at Caesars Palace.

And more pertinent, it’s the 50th anniversary of the first time Cheech Marin smoked pot.

“Yes, it was my first year of college, 1968,” says Marin, appearing with his legendary partner Tommy Chong at 8 p.m. Saturday at the Orleans Showroom. “My dad was a policeman in the LAPD, I was an altar boy, a choir boy, a straight arrow. But when I went to college, I was not living at home. I was off the leash!”

Marin was handed a joint at a party soon after he enrolled at San Fernando Valley State College (now Northridge State University).

“I’d been told that marijuana was so bad for you, that everyone who smoked pot was going to hell,” Marin says. “Then I smoked, and my first thought was, ‘Wow, what else are they lying to us about?’ I started questioning everything, starting with the war in Vietnam. It changed my life.”

Cheech & Chong were originally a comedy-club act in the early 1970s. They drew national fame after releasing a series of hot-selling comedy albums. Three of them reached the Top 5 on the Billboard album charts (“Big Bambu,” “Los Cochinos” and “Cheech and Chong’s Wedding Album”).

But their album and film success inevitably led to creative tension, and ultimately the duo split in the mid-1980s.

“Abso-freaking-lutely, we had a problem with success. You can gain kind of an attitude and your ego is out of control, and that happened with us” Marin says. “In any partnership, it’s hard to keep together two strong-willed partners. It’s hard to listen to each other’s (expletive), on both sides of the table. So it was like, ‘Let’s just separate now,’ but we never officially announced it. It was just that I was happier doing my own thing.”

Marin took on solo roles in the films “Born in East L.A.” in 1987, and “Tin Cup,” in 1996. He co-starred in the TV series “Nash Bridges” with Don Johnson, from 1996-2001, and has been a voice actor in several animated films, including Ramone the low-rider in the “Cars” franchise.

Marin says the Saturday’s stage show will reflect the duo’s respective talents, including some improve during a Q&A session and some musical moments. “We’ll have a lot from Tommy’s musical past,” Marin says. “We just played the Newport (R.I.) Folk Festival, and had a lot of fun there. The act is still really good, fans love it.”

Marin also an avid collector of Chicano art, and was the a champion of “Celebrity Jeopardy” in 2010, knocking off CNN’s Anderson Cooper and comic Aisha Tyler in the charity competition.

Marin has recently turned his affection for cannabis into a business: Cheech’s Private Stash. The company motto: “It will always be good.”

“We have 100 new strains every week, and it seems like everybody experimenting now,” Marin says. Asked how he manages to ensure quality control, he says, “I test it (laugh), I am in charge, but I have a lot of help, too.”

John Katsilometes’ column runs daily in the A section. Contact him at jkatsilometes@reviewjournal.com. Follow @johnnykats on Twitter, @JohnnyKats1 on Instagram.