Every June 4, the internet celebrates what it calls Killdozer Day. In 2024, Granby Mayor Josh Hardy closed town hall for three days around the anniversary and increased police presence. “Violence and destruction do nothing but hurt the Granby community,” Hardy said in an official statement. Twenty-two years later, the town and the myth are still not telling the same story.
Marvin Heemeyer arrived in Grand County in 1989. He was an Air Force veteran, a welder, a muffler shop owner. Neighbors described him as someone who would bend over backwards for a friend. Others knew him as a man who held grudges and acted on them. When the Town of Granby approved a concrete batch plant adjacent to his muffler shop in January 2001 — cutting off the only road access to his property — Heemeyer filed a lawsuit, complained to the EPA, and rejected a settlement offer from the Docheff family that would have provided him a free sewer easement. In October 2002, he began converting a Komatsu D355A bulldozer, purchased in California for $16,000, into an armored vehicle.
He worked alone for eighteen months, behind a wall he built inside his own shop. He sandwiched concrete between layers of steel plate, mounted external cameras feeding monitors in the cab, and installed gun ports. He stocked the cockpit with three rifles, three handguns, food, and water. When visitors stopped by, he lied about what he was building. In audio recordings made in the months before the rampage and mailed to his brother in South Dakota, Heemeyer said God had clouded their vision. “God built me for this job,” he said in an April 13, 2004 recording, thirteen days before the attack.
On June 4, 2004, at approximately 3 p.m., Heemeyer drove through the wall of the building and into Mountain Park Concrete. He demolished 13 structures over the next two hours — the concrete plant, Granby Town Hall, the police department, a bank, a utility service center, the offices of the Sky-Hi News, and the home of a former mayor. Every building had a documented connection to his disputes. Cody Docheff fired a pistol at the machine. Undersheriff Glen Trainor climbed on top of the moving bulldozer and fired 37 rounds from his service pistol. Three explosions were detonated against it. More than 200 rounds of ammunition were fired. Nothing stopped it.
The bulldozer got stuck in the alleyway of Gambles Hardware Store. A single gunshot was heard from inside. Heemeyer was dead from a self-inflicted wound to the head. Damage totaled an estimated $7 million. He was the only fatality.
Granby Town Manager Tom Hale told reporters on June 5, 2004, that Heemeyer had been angry over the zoning decision and the $2,500 code violation fine — the check he paid with the word “Cowards” on the memo line. “We felt he was venting his frustration,” Hale said. “We didn’t think he was going to do something like this.” Four people had heard Heemeyer say he was going to bulldoze the town. All four dismissed it.
Granby was not the first time a Colorado mountain town saw this. Six years earlier and 70 miles to the southwest, in Alma, Thomas Dean Leask shot and killed the former mayor on Feb. 28, 1998. The mayor was presiding over an Alcoholics Anonymous meeting. Leask then stole a town-owned front-end loader and rammed Alma’s town hall, post office, water treatment plant, and fire station in a four-hour rampage. The dispute was over water tap fees. Alma is Park County. Granby is Grand County. The Killdozer mythology treats Granby as an isolated event. It was not.
After Heemeyer’s death, the Grand County Sheriff’s Office released his audio recordings to media in August 2004. They ran nearly three hours. In prepper and anti-government online communities, the tapes became source material. Survivalist forums began marking June 4 as Killdozer Day. The phrase from his written notes — “Sometimes reasonable men must do unreasonable things” — spread across social media as a rallying call.
Megan Squire, a computer science professor at Elon University who tracks online extremism, told NBC News in 2020 that Heemeyer had become revered by extremist groups. “Killdozer represents the intersection between the libertarian ideal of small government and the militant fantasy of the Boogaloo,” Squire said.
The symbolism produced documented real-world results. In June 2020, Steven Carrillo was arrested on 19 felonies including murder after an ambush that killed a federal officer in Oakland, California. Before his arrest, Carrillo scrawled “I became unreasonable” in blood on the hood of a car — a direct reference to Heemeyer’s notes. Politifact documented the connection in February 2022.
Patrick Brower was publisher of the Sky-Hi News the day Heemeyer drove through his building. He later wrote the book Killdozer: The True Story of the Colorado Bulldozer Rampage and in 2018 presented it as a warning to the Northwest Colorado Council of Governments — a body covering five counties and 23 towns. His message: officials are dealing with an electorate that accepts the anti-government narrative without checking facts, and explicit threats from aggrieved property owners need to be taken seriously. “People out there in the world today are inclined to believe the anti-government narrative without questioning the facts,” Brower told the council.
Brower also argued that Granby officials bore responsibility for inconsistent enforcement. Heemeyer went nine years without connecting to the sewer system as required, pumped raw sewage into an irrigation ditch, and was fined $2,500 only after he was caught. The fine arrived a decade late. “My guess is that when Marv shot himself in that dozer that day, he didn’t really understand the full nature of public policy relating to his sewer hookup,” Brower told the council.
No documented policy changes followed the 2004 rampage. No Colorado municipal association protocols cite the incident. Brower made his case to one regional council, fourteen years after the fact. Whether that message reached beyond that room is not on the record.
The record that is on the record: Heemeyer rejected multiple settlement offers, dumped sewage into a public ditch, spent eighteen months secretly building an armed vehicle, fired on law enforcement during the rampage, and tried to detonate the town’s propane tanks. He left behind a target list that included names, not just buildings. In June 2024, the mayor of Granby — population 2,079 — closed town hall and called in extra police to get through the anniversary of that day.
Whether that makes Heemeyer a folk hero is a question the evidence does not answer. It is a question about what people decide the evidence means.
Support Independent Local Journalism — High Country Advocate was created as a real alternative to regional media that too often silences dissenting voices while taking sides in the political struggle. Producing in-depth, unflinching reporting like this series and others is expensive: servers, editing, research time, and legal review all add up quickly. If these articles have informed you or given you new perspective, please consider supporting HCA with a paid subscription — every subscriber helps keep this reporting strong and independent. 