It’s an otherwise unremarkable stretch of Interstate 70, just west of the Kansas border. There are the familiar large green mile-marker signs on the side of the highway; familiar, that is, with one exception.

Since the recreational use of marijuana was made legal in Colorado in 2012, the “Mile 420” post became a hot commodity. So hot, it kept disappearing — and the Colorado Department of Transportation got tired of replacing it.

The solution came with some out-of-the-DOT-box thinking: They shifted the spot by a hundredth of a mile, and turned Mile 420 into Mile 419.99.

There has been less sign thievery since the switch, but it hasn’t been a complete success. The Mile 419.99 sign has gone missing a few times too, but despite the occasional sticky green fingers the spot has become a destination. For some it’s just to see if the sign is for real, for others to maybe grab a few selfies. Still, perhaps surprisingly, the new signs have lasted longer than the old—the State of Colorado’s rare signage creativity seems to be paying off.

Update June 2019: The sign has been gone since 2017.