Montana is one of only 12 states with a single area code, and its residents have made those three digits part of the Treasure State’s brand. 406 adorns souvenirs, websites and even the names of businesses.

“The 406 area code is a unique part of our heritage in Montana,” said Montana Public Service Commission Vice Chairman Bob Lake, R-Hamilton. “It’s become such an integral part of our state’s identity that some businesses have built their entire brand around the novelty of our single area code.”

Growth in the state’s population — in particular, its number of cellphone subscribers — will eventually force the adoption of a new area code to accommodate more numbers. That had originally been expected to happen in 2019. But on Monday, the Montana Public Service Commission learned that 406’s reign will likely last into the early 2030s.

Lake attributes this change to the Commission’s 2013 decision to implement a policy known as “mandatory number-pooling,” which requires existing telecommunication carriers to make available numbers they are not using, and limits the amount of additional telephone numbers that can be assigned to new providers or providers requesting additional numbers.

“Basically it ensures that carriers are not sitting on a bunch of unused numbers, which could hasten the area code exhaustion date,” he explained in a press release.

The Federal Communications Commission has revised its predictions to take this policy into account, and now expects 406 to remain Montana’s sole area code until 2031.