When Rabbi Chaim Bruk moved from Brooklyn to Montana in 2007 with his wife, Chavie, to open the state’s first Chabad center, he pledged to put a kosher mezuzah on the doorpost of every Jewish home.

There are 2,000 Jewish families in Montana — that’s a lot of mezuzahs.

We learn about this pledge early in “The Rabbi Goes West,” and it becomes a central organizing principle in this smart and highly engaging documentary by Boston-based co-directors Gerald Peary and Amy Geller. It will be shown in three free matinee screenings at the San Francisco Jewish Film Festival.

Just as putting up mezuzahs gives Chabad rabbis a way to step into Jewish homes, watching Bruk putting up the mezuzahs gives the audience intimate access to the lives and beliefs of Montana’s Jews. It’s one of several through-lines that move this charming narrative along.

There are many films about Chabad, most of them fawning hagiographies produced by Chabadniks or their followers. This is not that. In just 75 minutes, we learn a great deal about Bruk, Jewish Montana, Chabad, and how Chabad interacts with other streams of Judaism. And we have fun doing it.

It helps that Bruk has a huge personality. He’s funny, intelligent and endearing. That’s typical of Chabad rabbis who are pioneers in a region, and it was smart of the filmmakers to focus on someone like him.

He and his wife are not typical, however, in one important way: Unable to have children, they have adopted five, including a young biracial boy.

“To all the racists out there, I say, come and get me,” he tells the camera. “I’m a Montanan, I’m Orthodox and I have a black child.”

Montana is a gorgeous state! The scenery is breathtaking — big skies, snow, lakes, mountains — and the film is shot beautifully, even the up-close interviews. That’s important, because a lot of the narrative involves talking heads, which could be deadly if not done well.

Those talking heads are Bruk and Montana’s three other rabbis, all from liberal denominations. The other rabbis don’t hold back when they talk about where they differ with Bruk and his brand of Judaism. Yet the conversations are always respectful, even though it’s clear that Bruk has stepped on a few toes while pursuing his mission to “touch every Jew.”

One of the film’s more compelling scenes is about the incident in winter 2017 when two of the rabbis were targeted by neo-Nazi hate. It was widely covered by the Jewish media at the time, but hearing Rabbis Francine Roston and Allen Secher talk about the phone calls they got, and how the aftermath was handled, is very powerful.

Above all, “The Rabbi Goes West” is about a haredi guy from Brooklyn who uproots himself from everything he knows to move to the Wild West. He’s come to change Jews, sure, by asking them to do more mitzvahs. But the power of Big Sky country changes him, too.

Living in Montana has, Bruk says, made him “a more thoughtful person, a more open-minded person.”

Peary and Geller bit off a lot with this film, and they have handled it just right. Put it on your viewing list.

“The Rabbi Goes West,” free screenings at 3:10 p.m. July 23 at CinéArts Palo Alto, 1:40 p.m. July 24 at the Castro Theatre in S.F., and 3:30 p.m. July 30 at the Albany Twin in Albany. sfjff.org