To watch Paul Thomas Anderson’s “One Battle After Another” is to take an expansive tour of California — from the northern tip to the southern border.

Over nearly three hours, Leonardo DiCaprio’s Bob evolves from revolutionary to fugitive to heroic father straining to save his teenage daughter, Willa, from his obsessive nemesis, Col. Lockjaw. On his journey, audiences get to to visit hidden corners of the state that even natives seldom see.

In an interview, Michael Glaser, the film’s supervising location manager, detailed several of the locations — including where that epic car chase was shot — that make up the compartmentalized character worlds he and his team helped create.

Our photographer visited them on a road trip. Have a look.

This is where Bob, the former revolutionary, and his daughter, Willa, have been living, away from prying eyes.

Their home is actually in the community of Kneeland, about 10 miles east of the city center.

When Bob learns that the obsessed Col. Lockjaw is in town looking for them, Bob flees through a tunnel and emerges through the forest outhouse you see here.

That’s really Teacher Fay’s, “a graveyard of cars” where a couple made parts for British cars, said Glaser, the location manager.

People often think of the Bay Area as Northern California, but Eureka is the true north — a coastal city in the land of redwoods about five hours north of San Francisco.

We looked for the pay phone that Bob uses to try to get a pivotal meet-up location …

… but a butcher working nearby said it was removed a while back.

The school Willa and her friends attend is in fact Eureka High School. Their teams are known as the Loggers.

The production had fallen in love with an old high school gym that was torn down before production, Glaser said. He had even tried to delay demolition. “We just missed filming in there,” he said. “It broke everybody’s heart.”

Normal Settings, Nefarious Doings

The house in Sacramento was the longtime residence of Ronald and Nancy Reagan when Reagan was serving as governor of California.

The board room is among a handful of scenes shot during two days on a soundstage, Glaser said.

The bank where an important robbery takes place was filmed 50 miles south, in Stockton, Calif.

But the subsequent police chase unfolds throughout downtown Sacramento.

Trying to hide from Lockjaw, Willa winds up at a nuns’ compound. That’s really the La Purisima Mission in Lompoc.

Willa is housed here for a time. But it does not take long for Lockjaw’s troops to find her.

La Purisima is the most completely restored of the 21 missions in California.

Scouts worked for more than a year to find the right mission, Glaser said. They eventually settled on La Purisima.

It is now a state historic park, which made it a little easier to film there, he said.

It is the only mission not owned by the Catholic Church.

They are deep in the desert, more than a four-hour drive east of Los Angeles along Highway 78. “A very dangerous highway,” Glaser said. “That’s why we loved it.”

The hills blind drivers, blocking their view of what is ahead — and behind — making them perfect for a chase.

And semis are constantly zooming along the single-lane highway at more than 80 miles per hour.

Another key road is known as the “Texas Dip.” It’s off Highway 78, the path into Borrego Springs, Calif., in a different county than the River of Hills.

The location manager’s team found the River of Hills by accident. They were visiting a nearby campground in search of a spot for a different scene.

Figuring out how to film that was “the biggest Hail Mary of the whole picture,” Glaser said.

That’s because Bob and his fellow revolutionaries are freeing immigrants at a detention center (where they meet Lockjaw), and the production needed an underpass, where they could shoot fireworks.

They found the Otay Mesa Detention Center, which shuts down after dark. But they still needed many approvals. Remarkably, the city, county, the Department of Homeland Security, Caltrans and the California Highway Patrol all agreed. Even the Border Patrol was “super cool,” Glaser said.

“I felt like I was in a fever dream,” he added.

Produced by Sean Catangui, Tala Safie and Amanda Webster