Prison and car museum display shares theories for why those numbers are on MHP insignia.

Although I’ve driven across Montana a few times, I’ve not (yet) been paid a visit by a Montana Highway Patrol officer. But during my recent visit to the Old Montana Prison & Auto Museum in Deer Lodge, I noticed a signboard parked near the left-front corner of museum’s 1977 Plymouth Gran Fury MHP patrol car 2727.

The sign is titled: “3-7-77: What does it mean?” and notes that those numbers — which herald the state’s history of “vigilante justice,” appear on the uniform insignia of every Montana Highway Patrol officer.

“From Absarokee to Zurich, tales are told to elementary, middle-school, and high -school students about ‘vigilante justice’ that was nothing if not swift,” we learn.

Helena, the state capital city, stages a Vigilantes Day with a parade and other events each year, but “perhaps the greatest tribute Montana has given them is the symbol 3-7-77 on the patch worn by Montana Highway Patrol troopers across the state.”

“We chose the symbol to keep alive the memory of this first people’s police force,” then-MHP chief administrator Alex Stephenson said at the time.

So, what’s the significance of those number 3-7-77?

Apparently, no one really knows.

“The original Vigilantes took an oath of secrecy which was strictly observed through the death of the very last one of them,” we’re informed. “While their true meaning remains a mystery, one thing is clear. Those numbers struck fear into the hearts of those who found them tacked upon their doors.”

The museum’s signage shares the four popular theories behind the numbers:

One: they represent the dimensions of a grave — 3 feet wide, 7 feet deep and 77 inches long. The symbolism: If a crook didn’t leave town within 3 hours, 7 minutes and 77 seconds, they would find themselves residing in a grave.

Two: Most of the early Vigilantes had come from California as part of the early Montana gold rush. California Vigilantes used numbers instead of names to identify themselves, and 3, 7 and 77 may have been the most prominent of those who settled in Montana.

Three: Of the original Montana Vigilantes, 3 were lawyers, 7 were merchants and 77 were miners.

Four: Some believe the original Montana Vigilantes were formed by members of the Masonic order, with 3 members present for the first meeting, 7 representing the number needed for a quorum and 77 the number of original Vigilantes attending their first official activity in the Montana Territory, the funeral of Mason William Bell.

This article, written by Larry Edsall, was originally published on, an editorial partner of Motor Authority.