It looked like a “Star Wars” sandcrawler, armor-plated and on massive tracks.

It was welder and mechanic Marv Heemeyer’s masterpiece, 85 tons of unstoppable motorized mayhem. Because that’s what he built it for.

“Tread” is a tale of a small town feud taken driven to its diesel-powered coup de grace. It has an operatic, unbelievable, large-than-life/”only in America” quality. And if you don’t remember this moment in time from 2004, it’s because Ronald Reagan died the day after Heemeyer’s drive of revenge through Granby, Colorado, utterly obscuring this Great Moment in White Male Working Class Rage.

Using interviews, actual news coverage, reenactments and a rambling, cassette-tape manifesto by the welder run amok, filmmaker Paul Solet paints a portrait of working class grievance, “good ol’boy” cronyism and venality, persecution complexes and petty grudges that become epic. Its portrait of small town provincialism suggests that it should go straight from theaters and streaming to just the right TV network — RFD-TV — where some rural soul searching is in order.

Yes, the “hero” of the piece is plainly paranoid, messianic and wrong. But as Solet’s film cannot help but reveal, that old joke has a hint of truth about it.

“Just because you’re paranoid doesn’t mean everybody ISN’T out to get you.”

Heemeyer was an Air Force vet who stayed in Colorado after his service, using the welding and mechanical skills he picked up in the military to make a business — a muffler shop — and a life for himself in Granby, population 1800 or so — just over the mountain from Boulder.

He had plenty of friends, a sometime girlfriend and a passion — snowmobiling. His work was respected by all and he ran a successful welding business.

But to hear him tell it, in this long, multi-tape suicide note he left behind, he crossed the wrong “legacy” businesses and families when he won a place to open his shop at auction. It took a decade of perceived insults, zoning and sewage distract hassles and lawsuits that he saw as persecution for him to have his hot tub epiphany.

Buy a huge Kubota bulldozer at auction, turn it into a tank and make himself an avenging angel on treads. God told him to do it. In his hot tub.

“You people needed to be taught a lesson,” he explains, on tape. “When you visit evil on someone, believe me, it will be visited on you.”

The overarching theme of Solet’s film is that there’s no feud like a small town feud. Get on the wrong side of the wrong person, and you can’t help but make associations that every other problem in your life will connect to them. Because they have friends, and relatives. And those friends and relatives are on this board, run that town office, or are even the mayor.

People like the local newspaper editor became — in Heemeyer’s growing rage — sworn enemies. We hear Heemeyer’s accusations first, and then denials, which colors our perceptions about who might be right, who might not be right in the head.

Those he accused come off as genuinely puzzled, or leave the viewer with the suspicion, “Yeah, Heemeyer’s a hotheaded assh–e, but so’s this liar.”

“No one realized how distorted it was becoming to him,” Ski Hi News editor Patrick Brower admits, his business targeted despite his professed best efforts to be fair and keep on the good side of a disgruntled local business owner.

The last third of the documentary is devoted to news footage or painstaking recreations of the “killdozer” rampage, and let me blunt about that. It’s 85 tons of pure catharsis, served up as entertainment. Which it is.

Make this story about a gun-nut slaughtering innocents — which it could have been, given the setting, the culture and Heemeyer’s on-tank cannon (a .50 caliber rifle) — and there’s no way anyone in good conscience could take it this way.

Instead, we watch a methodical, mechanical nut, with grievances (possibly) real and imagined, destroy the property of those he figures have wronged him. A friend recalls a Vin Diesel movie the 51 year-old Heemeyer kept in his shop, “A Man Apart.” I left “Tread” certain he must have seen that James Garner Army comedy “Tank.”

We see footage of townspeople gathered on the hill overlooking the tank-tantrum, and we get it. They gawked as we gawked, as news viewers around the world gawked. Everybody likes to see machines run amok. You’re already headed to Youtube to check out the news clips or the movie trailer there.

Businesses destroyed, lives shaken to their core, the cars of bystanders crushed, cops helpless to stop it — it’s awful and tragic, sure.

But it’s something to see, man.

MPAA Rating: unrated, violence

Cast: Marv Heemeyer, his friends and “enemies” in Granby, Colorado

Credits: Directed by Paul Solet. A Gravitas Ventures release.

Running time: 1:28