Marvin Heemeyer and the Story of Killdozer Day

By: Alyssa Miller | Published: Dec 06, 2023

What would you do if you saw a modified bulldozer rampage through your local town? This was a question many in Granby, Colorado, had to ask themselves as local business owner-turned-killdozer driver Marvin Heemeyer drove through their town in the middle of the day.

In what was referred to as the Colorado rampage, Heemeyer and his “Killdozer,” the name given to his modified bulldozer, destroyed half a tourist-friendly Colorado mountain town. Why did Heemeyer do this? To understand the Killdozer story, we have to pinpoint the moment that tipped off Heemeyer. Let’s get into it.

Who Is Marvin Heemeyer?

Born Oct. 28, 1951, Marvin John Heemeyer was an American automobile muffler repair shop owner and professional welder living in the quiet town of Granby, Colorado. Heemeyer’s friend John Bauldree said that the welder was a likable person, and Heemeyer’s brother stated that Heemeyer “would bend over backward for anyone” (via 9News).

A close up of Marvin Heemeyer

Source: WillyWumpLump/Reddit

However, many people, like Granby resident Christie Baker, claimed that Heemeyer was an unfriendly person. Baker claimed that her husband was threatened by Heemeyer after refusing to pay $124 for a muffler repair, according to The Denver Post.


Marvin Heemeyer’s Troubles Start

In 1992, Marvin Heemeyer purchased two acres of land for $42,000 at an auction. It was previously owned by Cody Docheff, who had a concrete plant. Heemeyer bought the land with the hopes of helping a friend build an auto repair shop on the land. The property, unfortunately, had some sewage issues.

Sewer pipe in the ground

Source: Public Domain/Rescue Pluming

The sewer company informed Heemeyer that he would have to put a 100-foot sewage line and lift station into the property at his own expense before they would annex the property into the sewer district, which is standard practice in the United States. This would have cost Heemeyer around $70,000 to install (via Academic Accelerator). Heemeyer could have also purchased a septic tank, which was a less expensive alternative.

Marvin Heemeyer’s Uphill Battle

Upset that he had to pay nearly twice the cost of his property to have a functioning sewage system, Marvin Heemeyer believed that the government should pay for the sewage line hookup.

View of Granby, Colorado from U.S. Highway 40 looking towards Rocky Mountain National Park. April 14, 2005

Source: Matthew Trump/Wikimedia Commons

In the book “KILLDOZER: The True Story of the Colorado Bulldozer Rampage,” author Patrick F. Brower reports that Heeymer believed this “injustice” was “extortion by government fiat.” Discouraged, Heemeyer instead opened a muffler repair shop on the property.

The Docheff Family vs. Marvin Heemeyer

The Docheff family was ready to expand their concrete business and were buying up land around their current lot in 1997. The town planning commission informed the family they needed a “Planned Development Overlay District” permit, and suggested that the family ask if they could purchase Marvin Heemeyer’s plot of land to keep the plant away from the hotels and businesses on Route 40.

A image of downtown Granby, CO.

Source: Billy Hathorn/Wikimedia Commons

On behalf of the family, Joe Docheff asked Heemeyer if they could buy the land. Heemeyer said he would sell it for $250,000, which the Docheffs offered several days later. Heemeyer claimed to have had the property appraised and discovered that it was worth $375,000. After the family offered $350,000, Heemeyer claimed another appraisal brought the value of the land to $450,000.

The Great Land Grab of Granby 

Unable to buy the land, the Docheff family began to buy land around Marvin Heemeyer’s property. Heemeyer attempted to purchase plots from underneath Docheff but failed. But Heemeyer wasn’t out of ideas.

The Docheff Family posing in front of cattle farm

Source: Docheff Dairy

Furious, Heemeyer publicly campaigned against the plant, attempting to create a movement based on environmental grounds. Hearings about the construction were packed, thanks to Heemeyer’s canvassing, with the public voicing their concerns. The Docheffs addressed the concerns by taking measures against dust, noise, and environmental issues. Opposition dwindled, and the construction of the plant was moving forward.


Marvin Heemeyer’s Final Straw Breaks

In 2001, the city approved the construction of a concrete plant, zoning the land next to Marvin Heemeyer’s for use. Joe Docheff attempted to make peace between their family and Heemeyer by offering to purchase a sewer line that would also connect to the plant free of charge if Heemeyer dropped his lawsuit against them, which would end up being dismissed in court.

Marvin Heemeyer Killdozer

Source: SkyHiNews

Heemeyer rejected Docheff’s offer. Instead, Heemeyer pumped the sewage from his filled septic tank with a gasoline pump into an irrigation ditch behind his property. Heemeyer also tried to connect to a neighbor’s sewer line and was caught and fined $2,500. Ordered to fix the connection sewer line he caused, Heemeyer protested, calling the requirements ordered by the judge a “form of terrorism.” An attorney at the judgment reported Heemeyer muttering, “I’m just gonna bulldoze this whole place to the ground.”


Marvin Heemeyer’s Plans for a Killdozer 

Knowing that he was fighting a losing battle, Marvin Heemeyer traveled to California to attend an auction in 2002. There, Heemeyer bought a Komatsu D355A bulldozer for $16,000 and shipped it to Granby with the hopes of reselling it.

A Komatsu Bulldozer on a dirty road

Source: Komatsu Australia/YouTube

After the bulldozer failed to sell and the sewer line created more issues for Heemeyer, he sold his muffler shop and the land to The Trash Co. for $400,000. Before leaving the premises, Heemeyer built a wall in his shop where he would illegally live and build his Killdozer. “It’s interesting how I never got caught,” Heemeyer wrote in a note (via Summit Daily).


Scrap Welding Projects Taking on New Form

Over a one-and-a-half-year period, Marvin Heemeyer worked on his Killdozer. He added armored plates, covering most of the bulldozer’s cabin, engine, and parts of the tracks. The armor was created by using scrap welding projects and mixing concrete poured between sheets of steel. Three gun ports were carved out and outfitted with a .50 caliber rifle, a .308 semi-automatic, and a .22 long rifle.

Man Welding Metal Bars

Source: Pavel Chernonogov/Pexels

The Killdozer inside was also modified. The cockpit had two monitors for Heemeyer to watch through a video camera that was mounted on the exterior for visibility, covered by a three-inch bulletproof plastic. Fans and an air conditioner were installed to keep Heemeyer cool during his rampage. The inside was crafted in a way that Heemeyer would seal himself inside with no way to get out.


What Happened on Killdozer Day?

On June 4, 2004, Marvin Heemeyer drove his machine out of the shop through the wall, then plowed through the concrete plant, the town hall, a newspaper office, a former judge’s widow’s home, a hardware store, and other homes. All the properties destroyed were connected to Heemeyer and his failed battle against the zoning committee.

A still image of the Killdozer

Source: Tap Rack Bang/Facebook

Authorities tried to destroy the Granby Killdozer multiple times, but the modified bulldozer was resistant to small-arms fire and explosives. For two hours and seven minutes, Heemeyer rampaged through the town. The governor recognized that the Granby Colorado bulldozer was unstoppable and considered authorizing the National Guard to attack with Apache helicopters and anti-tank missiles (via All That’s Interesting). Luckily for everyone, Heemeyer had wedged himself in the basement of a store and could not move.


The Death of the Killdozer Guy

Stuck and sensing the end was approaching, Marvin Heemeyer ended his life in the cockpit, determined to avoid capture. Afterward, authorities searched Heemeyer’s home and found notes and audio tapes that outlined his motives. In one of his notes, Heemeyer wrote, “I was always willing to be reasonable until I had to be unreasonable. Sometimes reasonable men must do unreasonable things.”

Marvin Heemeyer's armor-plated Komatsu D355A bulldozer aka Killdozer

Source: RidleyScottTowels/Reddit

The Killdozer was torn apart and sold across dozens of scrap yards, according to state officials. Many came to the town looking for pieces of the Killdozer to remember the absurd moment that would quickly become a subject of fascination in the true crime world.


The Legacy of the Killdozer 

Marvin Heemeyer’s mission wasn’t one of death. It seemed that the Colorado man only wanted revenge on the people and the town that didn’t feel the need to pity him. No one was killed by the accident, but an estimated $7 million dollars of damage was done in Heemeyer’s spite. It was a move that the people of Granby, Colorado, won’t forget for a long time.

A yellow Killdozer "Tread on Them" flag

Source: REDAEL/Amazon

While violence is never the answer, many look at Heemeyer as a folk hero. From Netflix’s Killdozer documentary, “Thread,” to Killdozer memes and Killdozer shirts with Marvin Heemeyer’s quote about reasonable men doing unreasonable things, this strange moment in history has become a cultural touchstone for many.