Zak (Zack Gottsagen) and Tyler (Shia LaBeouf) cut loose in "The Peanut Butter Falcon." (Photo courtesy of Roadside Attractions)

Newbie filmmakers Tyler Nilson and Michael Schwartz endured blanket rejections as they shopped around their screenplay for the uplifting late-summer surprise “The Peanut Butter Falcon.”

The indie feature arrives Aug. 16 in Bay Area theaters.

The co-directors/co-screenwriters, and best buds, pitched “Falcon” to countless studios, but few took a gander at the Mark Twain-inspired heart-warmer depicting the Southern journey and friendship of two outsiders, one a determined man (newcomer Zack Gottsagen) with Down syndrome and aspirations to become a wrestler and the other a renegade crab fisherman (Shia LaBeouf) with a haunted past and a deteriorating present. 

“We didn’t have any agents or famous friends,” Nilson said on the phone, a day before their film, which copped a 2019 SXSW audience award and is amassing glowing reviews — opened the previous week in select theaters. 

Disheartened, yet resolute, the cash-depleted duo persevered for five years to see “Peanut Butter Falcon” take flight, even pitching a tent in the Los Angeles woods to offset ballooning costs.

“We were 100 percent in to what we were doing,” Nilson said.

Why were Nilson and Schwartz — who grew up in Santa Rosa, lived in Berkeley (and gives a shoutout to Cheese Board Collective), Muir Beach and San Francisco — so passionate about their first feature? It was mostly due to star Gottsagen — whom they met at a camp for performers with disabilities.

Tyler Nilson, left, and Michael Schwartz shot “The Peanut Butter Falcon” in 31 days.

Instantaneously, the two — who previously partnered on commercials and short films — recognized a star was waiting to be born; the trio became insta-friends.

“We always knew Zack had talent,” Schwartz said. “He just needed an opportunity. He was a very compelling character and helped us shape this movie in a lot of ways, down to the content and the dialogue. I knew in my life experience everybody who would spend time with Zack would then love him and want to spend time with him. It is nice to see the world is as welcoming as we would want it to be.”

A concern from the get-go was to keep production costs low. Nilson’s background helped.

“Tyler grew up in the Outer Banks (of North Carolina) so we knew we could shoot without permits for free and people had boats they’d let us borrow. … We (then) learned how to write scripts. We wanted to tell a hero’s journey and kind of live in that Mark Twain-inspired world.”

The inspiring drama, filmed around Savannah, is intended to remind audiences of Twain’s classic, “The Adventures of Huckleberry Finn,” particularly when it plunks its three central characters who are fleeing their suffocating circumstances on a raft. 

Zak (Gottsagen) runs away from an older adult care facility where he’s been dumped; Tyler (LaBeouf) tires to elude outraged fishermen (John Hawkes and Yelawolf) for his rebellious, reckless misdeeds; and Eleanor (Dakota Johnson), a by-the-book worker from the care facility, tries to shed the chains of bureaucracy.

But “The Peanut Butter Falcon” probably wouldn’t have been made if Schwartz, Nilson and Gattsogen hadn’t shot a five-minute trailer. That nabbed the attention of producers, some of associated with indie sweethearts, “Little Miss Sunshine,” “Nebraska” and “Mudbound.”

“Very quickly we were taken more seriously and we got an actor or two to sign on and wound up with the right financer/producers who have a history of family members with Down syndrome,” Schwartz said.

“So they were able to make a risky business decision that’s based more on hearts and the stories that they wanted out there than strictly business and money making, which is really important. I don’t think this film would have gotten made without them.”

Early in the process much attention was paid to the in-the-headlines LaBeouf. He was released from a brief stay in jail in 2017 due to public drunkenness, and went directly to filming. Both Nilson and Schwartz praise the talented actor for his commitment.

“Shia showed up on the set and got a job on a crab boat because he wanted to be authentic and part of that world,” Nilson said. “We got him that job and it was about a three-hour drive south in Georgia. We picked him up in an old ’72 Ford Ranger and we had two old, gross muddy tires in the back, one Zack sat in and the other Shia sat in.”

The outpouring of support from crew and cast, including actors Bruce Dern, Jon Bernthal, John Hawkes and a scene-stealing Thomas Haden Church — is deeply appreciated. 

“I’m so grateful to everyone who contributed,” Schwartz said. “They (actors) all did it at the minimums because we didn’t have any money.” 

They’re also proud that this one of the handful of films featuring a lead character/actor with Down syndrome.

“I sort of think it’s a moon landing,” Nilson said. 

Equally, it’s a film that boosts the spirits without being overly sentimental. 

“That’s why I wanted to lean into a simpler story about people who love each other,” Nilson said. “It’s not political, but it’s also an example of people who can love each other. 

“I think the world would be a better place if people loved each other a bit more.”