Here’s a documentary about unflappable, relentlessly optimistic educators and “The Bad Kids” they’re guiding — or dragging, kicking and sleeping (in class)– towards a high school diploma.

Black Rock High School is in scenic but remote and limited Joshua Tree, California, where as U2 taught us, “the streets have no name.” The place may be pretty, but growing up there makes it feel like the deadest of dead-ends.

Black Rock is a school of last resort for kids who have been messing up, all over the region. They’re from broken homes, have access to drugs and what little supervision they seem to have is generally disinterested. They have probation officers, some of them. Others have become teen parents, repeating the endless cycle of poverty, neglect and abuse that brought them into the world.

Whatever their home situation, they’ve been kicked out or flunked out of the schools where they started. Black Rock gives them a shot at collecting the credits, as juniors and seniors, to graduate.

The idea fomented here is to give each and every one of them a shock to his or her system. The principal, Vonda Viland, greets each busload of kids by name. Hugs are doled out, no strings attached. And the rest of the staff follows suit, calling the students at home when they are no-shows, driving out to pick them up, giving them a generous dose of “We care about you” for the first time in many of their young lives.

It’s bracing and inspiring, what filmmakers Keith Fulton and Leo Pepe show us in that first hour. Kids get motivated, act reasonably, learn anger management and seem to appreciate the attention.

But during the course of a school year, as the movie zeroes in on drug dabbling musician Joey, abuse victim Jennifer and teen baby daddy Lee (and his girlfriend Layla), we see pitfalls, backsliding and attempts to give up.

Some will succeed, at least one is sure to fail. That’s the way such documentaries (this one had Sundance Institute sponsorship) work. That’s also the way of things in such “last resort” high schools all over America.

Viland keeps a sign, “The Witch is In,” on her office door. But her every breath contradicts that. Kids are arm-twisted into second, third and fourth chances. The tough love can be compassionate — “Your daughter is me, 40 years ago.” It can be funny in the ways she demonstrates that the best parenting begins with the phrase, “I’m WATCHING you.”

“Who’s that suckin’ on your neck, there?”

And it is blunt. “Get your butt up every day and get on with it.”

Joey has to be cajoled out of his “I don’t want to DO high school” malaise.

Lee must learn to do the math that explains his dilemma in harsh financial terms, the eighteen years of child rearing he and Layla have set themselves up for.

Jennifer has to stay focused and forgive or forget the parents who might be holding her back.

Random snippets of mini-counseling sessions pick up “I really DO want to get out of that trailer” and “How can I believe in me when I don’t believe in myself?”

They’re not little angels. They pass off excuses — excuses more raw than most, but still excuses — like any slacker. They sass Ms. Viland and the teachers, get in fights on the bus and flip off the bus driver.

But their struggle, and the Herculean efforts of the staff — veteran teachers, all of them, bringing in guitars to reach a kid whose only interest is music, weeping over a child they know is heading into a homeless shelter after the bell rights — to give these hard-luck teens at least a shot at making something of themselves, is inspiring.

And as touching as the movie can be as every graduate is given a farewell full of love and group support, “The Bad Kids” makes us appreciate the awe the graduates must feel at clearing this first all-important life-hurdle. The teachers know that these are the littlest of victories. But they also know, given all their bad circumstances and bad habits, that a little cheerleading goes a long way to egging on the kids still in the system, still aching for that one last nudge from adults who care.

MPAA Rating: Unrated, with some profanity, discussions of drug abuse

Cast: The staff and students of Black Rock H.S.

Credits:Directed by Keith Fulton and Lou Pepe. A FilmRise release.

Running time: 1:41