Production appears to be underway in Northern California for the Leonardo DiCaprio movie with the working title “BC Project” after residents reported clusters of police cars, camera crews and Warner Bros. reps in the Redwood Region earlier this week. The film also stars Sean Penn and Regina Hall, and is written and directed by auteur Paul Thomas Anderson, who is known for classics like “Boogie Nights,” “There Will Be Blood” and his latest coming-of-age romance “Licorice Pizza.” Details surrounding the plot of the film remain under wraps, but more information was quietly released on its IMDb page in recent days. Producers Sara Murphy (“If Beale Street Could Talk”), JoAnne Sellar (“There Will Be Blood”) and Adam Somner (“Licorice Pizza”) are now attached to the project, as is on-set painter Mike Reiber (“Babylon.”) Extras casting directors Tracy Dixon (“Super 8”) and Kelly Hunt (“Ford v Ferrari”), whose names were listed on a local casting call for “BC Project,” are also now confirmed among the crew. Meanwhile, Eureka was officially named as at least one of the filming locations, and production began on Jan. 21, per IMDb. It makes sense that the film now has a confirmed costume designer, too: Mark Bridges of “The Artist.” The staff of the Hospice Shop Thrift Store in Arcata said that over the past two weeks, representatives for the film have shown up at their store on H Street “at least four to five times.” The crew spent at least an hour at the thrift shop putting together a massive pile of men’s clothing, fitnesswear and some dresses, Tia Baratelle, director of development for Hospice of Humboldt, told SFGATE. “The first time they checked out, our manager was ringing them up, and asked if they ran a consignment shop or something because of how much they were buying,” Baratelle said. “It was at least a thousand dollars’ worth of clothes. That’s when one of the guys looked at her and said, ‘We’re from that movie.’ Of course she knew what he meant.” As they were leaving, Baratelle said one of the crew then jokingly asked the manager, “Do you think we have enough stuff?” She told him they could “always come back if they didn’t.” On subsequent visits, they returned in search of home decor, including flowerpots and teapots, as well as pet collars and leashes and even more clothing. “They’re totally tight-lipped and aren’t sharing details, but said, ‘You might be seeing it in the closets.’ It might be used for props,” Baratelle said. While Baratelle admitted she’s not much of a movie buff, and seemed pretty nonplussed by all of the hubbub surrounding recent filming — “I’ve lived up here since ’99, and it happens pretty often,” she said — she’s excited to check out the movie once it’s released in theaters, and wouldn’t mind seeing a celebrity or two. “Whether it’s from movie folks or not, we appreciate any support we can get,” she said, noting all of the proceeds earned at the thrift store go toward Hospice of Humboldt’s mission to provide grief services, palliative and hospice care in the area. “It’s great that they’re supporting our local economy.” Chris Reynoso, who runs Cafe Brio in Arcata, said he’s also noticed some production assistants from the film grabbing breakfast at his business and paying with a card that was labeled “BC Project.” Some of them also bought a “hippie-looking” recycled wood wall hanging made by local artist Zak Shea that he suspects may be used in the film. “We’re all thrilled,” Reynoso said. “It’s nice they were here because they helped bring in some business during a normally slow time of year.” On social media, people posted sightings of an unusual line of police cars going northbound along the safety corridor on Highway 101 and slowing traffic near Arcata earlier this week. One resident shared a video from the window of Gallagher’s Irish Pub in Eureka of more police cars with their lights flashing, followed by a Porsche Cayenne with a crane car mount affixed to it as they drove along Redwood Highway. A Warner Bros. truck was also seen parked near the Domino’s in Arcata earlier this month, Redwood News reported. Cassandra Hesseltine, film commissioner for the Humboldt-Del Norte Film Commission, confirmed with SFGATE that a project was being shot in the area but could not verify how long production would last, nor its ties to the Anderson film. She noted residents may notice “some noise levels” in the coming days, but that shooting wouldn’t be taking place in the middle of the night and was unlikely to disrupt anyone’s sleep. “The biggest thing we want people to do in the near future is to pay attention to roads and rerouting of activity,” Hesseltine told SFGATE over the phone Tuesday. “People will be notified of impacts regarding road closures or ITC [intermittent traffic control] and we’ve asked that production has flaggers and safety officers on site. In turn, we ask people to take their time, be careful and appropriate if they see anything. We appreciate everyone’s patience at this time, and anything anyone runs into is just temporary.” The Humboldt County Public Works Department told SFGATE on Tuesday that no road closures are related to filming at this time. One of the previously announced collaborators on “BC Project” was casting director Cassandra Kulukundis (“Inherent Vice”), who in 2022 posted a casting call for an Anderson film in need of a “15 to 16”-year-old “teenage girl who excels at Martial Arts,” per World of Reel. It’s unclear if the notice is related to another project the director is working on, but notably, Eureka High School shared a casting call last month for “a big movie” that was going to be filmed on campus, seeking paid extras aged 16 and older. SFGATE reached out to the school district for confirmation Tuesday, but was told in an email that “Eureka City Schools is unable to discuss any of the details regarding our involvement in the project, in any form, due to signed Non-Disclosure Agreements.” As more details are likely to emerge in the coming weeks while shooting continues, Hesseltine is asking people to be respectful of the cast and crew involved. The film commission office has been “flooded with phone calls” before, which can be more disruptive to production than people may realize, she said. “It’s interesting what happens when people get excited,” she said. “We want them to be, because that keeps the industry going, but there’s a point that it becomes a burden, and it becomes unsafe, even for a film commissioner.” She asked locals and film enthusiasts to be understanding if she can’t answer all of their questions right away — the payoff will be worth it. “We want to celebrate a movie when it comes out,” she said. “I know it sounds like we’re all being snooty or secretive, but we have to protect the project, the people involved and the intellectual property, and need folks to cooperate in order to do that.”