Colorado's Mile Marker 420 Became 419.99 to Stop Thieves

Somewhere along Interstate 70 near Stratton, Colorado, drivers encounter something peculiar: a highway sign reading "Mile 419.99." Not Mile 420. Not Mile 419. Exactly 419.99—like someone couldn't quite commit to rounding up.

This oddly specific number isn't a surveying error. It's the Colorado Department of Transportation's creative solution to chronic sign theft.

The 420 Problem

In marijuana culture, 420 has special significance—it's slang for cannabis consumption, particularly on April 20th (4/20). This made Colorado's Mile 420 sign irresistible to souvenir hunters, especially after the state legalized recreational marijuana in 2012.

The sign vanished repeatedly. Each replacement cost taxpayers money, and the empty post created confusion for drivers trying to navigate. CDOT needed a solution that wouldn't require constant replacements.

The Decimal Workaround

In 2013, transportation officials installed "Mile 419.99" instead. The logic was simple: the sign technically marks the same location, but the fractional number makes it less appealing as a trophy. Who wants to steal a math problem?

The strategy drew inspiration from Washington State, which faced similar issues with its Mile 420 marker on State Route 20. Other states have tried different approaches—some install extra-secure bolts, others simply don't replace stolen signs.

Colorado also moved its Mile 69 marker half a mile down the road and relabeled it Mile 68.5, preventing theft of another number with juvenile appeal.

Plot Twist: They Stole It Anyway

The decimal deterrent worked... for a while. The 419.99 sign attracted international media attention in January 2014 after CDOT tweeted about it, making it famous in its own right.

Eventually, collectors started stealing the replacement sign too. As of 2019, the Mile 419.99 marker had been missing since 2017. You can't win.

The saga illustrates a universal truth about human nature: tell people something is un-stealable, and they'll steal it just to prove you wrong. Colorado's decimal solution has become more famous than the original problem, turning a bureaucratic workaround into a roadside legend.

The sign remains a popular photo opportunity when it's actually in place—which is increasingly rare.