“Where’s John Dutton when I need him?” Costner asks talking about his four-part “Horizon” project

Kevin Costner is unsure where he’ll be when “Horizon: An American Saga – Chapter 1” hits theaters Friday.

The former “Yellowstone” star, 69, imagines he’ll be at his Santa Barbara, California, home, definitely not popping

into nearby movie theaters to see how the first of his planned four-part Western movie series and passion project is playing before crowds. “I might be on my back somewhere, just rolled up in a fetal position, like it’s all over,” Costner tells USA TODAY with a laugh. The project has coincided with considerable drama offscreen over the past year – a messy divorce from second wife Christine Baumgartner and an agonizingly drawn-out split from the “Yellowstone” franchise.

Speaking from his movie studio where he’s editing his second epic, “Chapter 2” (due Aug. 16), Costner’s stubbornly blond hair is disheveled and his quarter-zip sweater is unapologetically rumpled. Yet he’s attentive and focused discussing the sprawling movie project he co-wrote, directed, produced, stars in and mortgaged his home to finance.

“Horizon: Chapter 1,” which has taken shots by early critics, is finally going to the ultimate judge – the movie public.

You shove something out into the water, and now it’s not yours anymore. But you honestly know you did everything you possibly could. I know (“Horizon”) will be watched,” says Costner. “To what degree, that’s what we’ll see, right?”

That is the $100 million question, the reported budget for the R-rated, 181-minute first chapter. Costner does not even appear until 66 minutes into the movie as Hayes Ellison., a mysterious gunslinger who crosses paths with a local courtesan, Marigold (Abbey Lee).

The duo’s travails are just two of the myriad stories, with 170 speaking parts, in the often brutal tale of post-Civil War westward expansion.

“In the second feature, things get harder for them. And the third film, things don’t change,” says Costner. “The West was hard.”

What’s Costner’s financial stake in ‘Horizon’? ‘I try not to let it keep me up at night’

Costner first started dreaming about the story in 1988, imagining five films. Even cut down to four, it’s a supremely ambitious project for which he’s pieced together financing. He says the cost of the first two “Horizon” movies, required “a lot more” than the $38 million he copped to personally putting down in previous interviews.

“I try not to let it keep me up at night,” says Costner. “Entrepreneurially, I just figure out a way. Maybe I’m a mongoose playing with a cobra.”

The principled and proudly stubborn Costner went through similar drama with predictions of doom for 1990’s “Dances with Wolves” (a box-office hit that went on to win seven Oscars, including best picture and best director) and 1995’s actually troubled “Waterworld,” which eventually eked out a profit. “Horizon” is a fourfold gamble.

“I can’t ignore where my heart wants to go,” says Costner of the “Horizon” spend. “I’m not a fool, but it feels foolish. I don’t honestly know why I do the things I do. I’m not hurting anybody, and it’s my intention to bring a solid piece of entertainment.”

By all accounts, Costner was outwardly unaffected by his burden during the 52-day shoot in picturesque Moab, Utah.

“I’m sure he was thinking about putting up his land to help finance it and other stuff he had going on,” says Luke Wilson, who plays Matthew Van Weyden, the captain of a wagon train. “But he just focused on the work. The guy is cool under pressure. I couldn’t believe it.”

Why Costner announced ‘Yellowstone’ departure after editing ‘Horizon: Chapter 2’

Leaving a “Chapter 2” editing session last week, Costner officially ended speculation about whether he’d return for the fifth and final “Yellowstone” season as rancher John Dutton.

After a prolonged battle and negotiations with creator Taylor Sheridan and Paramount Studios over pay and shooting schedules, exacerbated by Costner’s ambitious movies and Sheridan’s TV universe, Costner put the nail in the return coffin in an impromptu June 20 video.

“I just said, ‘Bring the camera over here a second.’ I just wanted to get it done,” says Costner, who spoke directly to “Yellowstone” fans, saying, “I just wanted to let you know that I won’t be returning.