The organizing starts around Thanksgiving and doesn’t let up through the New Year. For Christine Vachon and Pamela Koffler, the co-founding producers of the indie powerhouse Killer Films, the Sundance Film Festival is an annual trek through the snow that dates back three decades. The duo have sold 25 films here, from the 1995 Todd Haynes drama “Safe” starring Julianne Moore to 2002’s “One Hour Photo,” featuring an eerie turn from Robin Williams.

To listen to them reminisce about their memories from past visits to Park City is to step into a time capsule. “I definitely have the nostalgia stories of bringing physical cans of film,” says Koffler. “My hands were cold and the metal was cold as I put it on the luggage belt. It was a physical experience that has disappeared.”

This year, Killer Films came to Sundance with four more titles that capture the New York-based production company’s eclectic and varied tastes for small movies. There’s “Dina,” a documentary about an oddball Philadelphia couple (she loves the Kardashians and he’s a Walmart door greeter) that premiered on Friday night to strong reviews.

Miguel Arteta’s “Beatriz at Dinner” is a buzzy dark comedy starring Salma Hayek as a medical healer. Michelle Pfeiffer returns to movies in “Where Is Kyra?” as a lonely woman grappling with the death of her mother. And finally, “Lemon,” from first-time director Janicza Bravo, centers on a washed-up actor struggling with a mid-career crisis.

“It’s a healthy time, especially when you think of all the different ways a movie can go out into the world,” Vachon says. “Of the four movies we sold last year”—including the Todd Solondz comedy “Weiner-Dog” (Amazon Studios) and the college hazing thriller “Goat” (MTV Films with Paramount Pictures)—“not one of them went to a so-called traditional indie distributor. I never would have said it a couple years ago.”

She admits that she’s sometimes “shocked” at which movies go where. But they’ve learned to tell their filmmakers to downplay their expectations as they brave the city storms and slow buses circling around town.

Vachon, the seasoned producer behind such indie darlings as “Velvet Goldmine,” “Boys Don’t Cry,” “Far From Heaven” and “Carol,” has served twice on the Sundance juries. But she first came to the festival as a filmmaker with the short movie “The Way of the Wicked,” a satire of the Catholic Church. She bunked in a dorm-like dwelling, provided by the festival, with an aspiring story teller name David O. Russell.

She recalls the year she raced out of the screening for “Safe” to make it to the Egyptian Theater for a late-night screening of “Kids.” The Larry Clark picture hadn’t officially made it into Sundance, but distributor Harvey Weinstein — then at Miramax — rented out the venue on Main Street to create buzz. After that, Sundance stopped the practice of allowing producers to screen movies that weren’t part of their lineup.

“I do remember seeing ‘Precious’ and having no preamble,” says Koffler of her 2009 trip to Sundance. “It was just a pure discovery.” And 15 years ago, one of her favorite moments was after the Q&A of “One Hour Photo,” when Williams launched into an impromptu 20-minute stand-up routine. “It was that intimate festival experience when something unexpected happens,” she says.

Against the backdrop of late nights and chili parties (which Vachon used to make at their condo), there are still difficulties associated with juggling so many films at once, especially when premiere times overlap.

“After shaking our fists at the Sundance Gods…” Vachon says.

“We divide and conquer,” Koffler adds.

Last year, there was a mild panic attack, after a stack of tickets for the “Goat” premiere disappeared. Fortunately, they were able to sneak the right VIPs past the volunteer ushers.

“It’s like planning a wedding,” says David Hinojosa, the company’s head of production and development. “You have to make sure you include everybody. We have four weddings. That’s better than three, because it would have been hard to tell one of our kids that they couldn’t go.”