“Romancing the Stone” looks like a fun adventure romp onscreen, but making the Michael Douglas-Kathleen Turner movie that turns 35 this week was no stroll through the jungle. There were alligators, mud and plenty of back-and-forth with the studio — not to mention a tragedy after it opened.

The romantic comedy adventure opened March 30, 1984 and ended up as the eighth-highest grossing film of the year. It won the Golden Globe for best comedy or musical, and Turner took home the Globe for best actress in a comedy or musical.

Following in the footsteps of blockbuster “Raiders of the Lost Ark,” “Romancing the Stone” was a real game changer career-wise for star-producer Douglas, who became an even more popular leading man; Turner, who proved she was more than a femme fatale; and Douglas’ friend Danny DeVito, who became a bankable actor and director.

Director Robert Zemeckis went on to become one of Hollywood’s major filmmakers, earning an Oscar for 1994’s “Forrest Gump”; DP Dean Cundey worked on several more films with Zemeckis, receiving an Oscar nomination for 1988’s “Who Framed Roger Rabbit”; and composer Alan Silvestri still collaborates with Zemeckis.

But “Romancing the Stone” was also a bear to make on location in the jungles around Veracruz and Hidalgo in Mexico where the production was beset with rain, mud and creepy crawlies. And of course, all of the stunts and action sequences were done live.

“It was very, very tough,” said Zemeckis. “When the movie was over, I said to my agent who gave me the script, who is now my partner — Jack Rapke — if another script ever comes across your desk that has a slug line in it that says ‘Exterior. Jungle. Night. Rain.’ Never send it to me.”

“We had all kinds of things with the rain,” noted Cundey. “I remember one incident we were on the dirt road, just above the mud slide sequence where Kathleen and Michael go down the slide. We were sitting down preparing for something and there was a little rumble behind us. We looked across the road and the cliff had slid down and covered half the road. Had somebody been standing there, they’d have been covered with mud, or injured.”

Speaking of injuries, that mud slide gave Turner an abrasion worth several stitches. And when Douglas grabbed the tail of an alligator who had eaten the titular stone, the reptile gave him two powerful whacks in the face.

Douglas recalled that the gator, whose jaw was wired shut by trainers, dove into the bay after attacking him.

“We were looking for him,” said Douglas. “Finally, we heard some people yelling a little further down. It was a night sequence and we moved the lights over to where it was. What we didn’t know was the wire had gotten loose and gotten off.”

The two trainers took a boat over to where the gator was and got into the water. “The worst thing happened,” said Douglas. “The alligator took the guy’s hand and spun and took him down and under.”

The other trainer, who was also the man’s brother, went down and wedged the gator’s mouth open to rescue his brother.

“We got him to the hospital in time. His hand was pretty mauled, and he lost a lot of blood. I went to see him. He wanted to whisper something to me, and I leaned over, and he said, ‘My Rolex.’ It turned out he saved losing his hand because the alligator bit down on his watch. We went back to the location, dove in the water and we found this Rolex watch.”

Was it still working?

“I don’t know,” replied Douglas. “It would have been a good commercial.’’

With “Romancing the Stone,” the late screenwriter Diane Thomas created memorable characters and a clever premise: plain jane Joan Wilder (Turner), who writes steamy romance novels featuring a feisty heroine and a handsome adventurer, finds herself in the jungles of Colombia when she gets a frantic call from her sister who has been kidnapped by antiquities smugglers. Joan, of course, is like a fish out of water in the jungles until she’s saved by hunky exotic bird smuggler Jack Colton (Douglas).

There, the two get into more dangerous escapades than in any of her novels.

Douglas loved the script from Thomas, who had been working as a waitress, and was willing to pay. “I remember being criticized for paying so much money for a first-time screenwriter,” he noted. “I said, ‘Well, I don’t care if it was the first time or the tenth time, if the material is good, then the material finds its own value.‘”

When it came to writing the 1985 sequel, “The Jewel of the Nile,” Thomas was busy working on various projects. Still, said Douglas, “she came in and did a little doctoring, a little work for me on the sequel script.”

But what could have been a promising career in screenwriting was cut short.

Thomas, Douglas said, had always wanted a Porsche.

“So, the last time I saw Diane was when I went out to the parking lot and showed her the Porsche that I got her,” he explained. “About only about two months later, she got killed in the car.”

Her boyfriend had been driving when the Porsche struck a telephone poll. Thomas was only 29 when she died.

Though Douglas had won the Oscar for producing the 1975 best picture winner “One Flew Over the Cuckoo’s Nest” and had produced and appeared in such films as 1979’s “The China Syndrome,” he was thought of more as a television actor due to his starring role in the 1970s detective series, “The Streets of San Francisco.”

“In those days, there was a tremendous amount of separation between television acting and film acting. I wanted to try to get the part, it was very difficult,” Douglas said.

Box office names Clint Eastwood and Burt Reynolds were bandied about to play Jack. Eventually, Douglas was able to hire himself.

As for director, Zemeckis had caught Douglas’ attention with his second film, 1980’s “Used Cars,” which received strong reviews despite underperforming at the box office.

“Michael came to me,” said Zemeckis. “Michael was always a champion of mine. He really kept saying to the studio, ‘I really want the energy that’s in “Used Cards” to be in this movie.’ There was a sort of feeling of we were all on a mission.”

“There was an innocence about the production with all of us,” said Douglas. “It was a kind of location that no studio wanted to come down and visit. We were on our own.”

The studio’s top choice to play Joan was Debra Winger. “She was doing ‘Terms of Endearment’ in Texas and we did stop to see her,” said Douglas. “We couldn’t get a direct answer whether she was committed or not and we had concerns after being down [to Mexico} with Bob on locations and seeing how difficult it was going to be. We were going to need somebody to be a total team player. “

And that was Turner.

“’Romancing the Stone’ was thrilling,” she said. In fact, it was just the project she needed. After a star-making debut as a sexy femme fatale in the 1981 noir “Body Heat,” Turner “had to fight right away to get out of that rut” of being typecast. Her role in Steve Martin’s 1983 comedy “The Man with Two Brains” helped turn her image towards comedy.

“And then when we came to ‘Romancing,’ it’s like, ‘Yeah, okay, she’s sexy and she’s funny but can she be insecure and demure?’ So, then you go in with cut-offs, baggy clothes and no makeup and prove to them that you can be. But it takes so much to convince them.”

She described making the movie as “really fun. It was really a boy’s club, but they let me in because I’m a tomboy.”

That willingness to get muddy came in handy when Turner had to do a scene that involved walking through a marshy area filled with gators. “The trainer, the one who later almost lost his hand, said when they are really [sleeping], they are not so dangerous. But when they start to open their mouth, that’s their power. So, when they start to open their mouth, you step on their head. I said, ‘Like that’s going to happen.’ And they end up cutting the whole damn scene after I did it.”

“As the producer of this show, I was so appreciative of Kathleen,” said Douglas. ”She was just great in it. The situations that we put her in — I just could not imagine any other actress doing that. I was totally enthralled with her.”

And after making “Jewel in the Nile” and DeVito’s dark 1989 comedy “War of the Roses,” Douglas and Turner are reuniting for an episode of “The Kominsky Method,” Netflix’s award-winning comedy series starring Douglas and Alan Arkin. Turner will play one of Douglas’ ex-wives, who is a physician with Doctors Without Borders.

“It was just great,” Douglas said, of shooting the Season 2 episode. “She’s got that wonderful, great voice and acerbic style. It’s not the tone of ‘Romancing.’ It’s more the tone of ‘War of the Roses.’”

It’s no secret that the “studio was very negative” when executives saw the first cut of the film, Douglas said. Zemeckis added, “It wasn’t really like we had a big screening or anything. It was just the main creative executive. We were just kind of looking at it and realized we needed to shore up a lot of Kathleen’s [storyline] — all that stuff at the beginning where she’s generally in her apartment writing by herself. We went back and shot that stuff and it helped her character a lot.”

Still, Zemeckis was fired from his next project for the studio, 1985’s “Cocoon,” before “Romancing” was released. “Cocoon” was given to Ron Howard to direct.

“What happened was for some reason, the guy who was the head of physical production at Fox at the time, he had it out for our movie,” said Zemeckis. “While we were down in Mexico shooting, we found out later he was spewing all this vitriol about how we’re out of control and this director doesn’t know what he’s doing.”

The “Cocoon” producers, Zemeckis said, were “hearing all of this stuff constantly coming out of Mexico. They got nervous, so they fired me. After they saw the movie, they wanted to hire me back on ‘Cocoon.’ I just sort of kind of politely declined after that.”