Snow and ice severed a fiber-optic cable southeast of Libby Wednesday night to create sporadic cell phone and Internet service for customers in northwestern Montana.

Bonneville Power Administration crews have been working on the fiber-optic cable, located in the Silver Butte area south of Highway 2 and 30 miles southeast of Libby, since Wednesday evening, BPA spokesperson Doug Johnson said.

The fiber-optic line provides Internet and is leased out for other uses, as well, such as a landline that connects cellular phone towers. When the line was damaged, several cell phone towers in northwest Montana went out of service, according to Wesley Brown, an Alltel corporate spokesperson.

“The towers themselves are connected to landline,” Brown said. “When their fiber optic (line) was cut, it knocked out 13 towers.”

Because cell phone companies share towers, it affected subscribers from all providers, Brown said. With 13 towers out, phone traffic had to be re-routed, causing some people to get an “all circuits are busy” message when dialing out.

“Our network folks try to re-route the traffic on to other towers so that customer’s service won’t be affected,” Brown said. “It affected some outgoing calls of our customers.”

By Friday evening, eight of the 13 towers were back up and running, according to Brown. 

BPA crews are still working on the fiber-optic line, which, because of harsh weather and the mountainous terrain, can only be reached by snowmobiles, Johnson said.

Because Internet and cell phone service can be rerouted to other fiber optic lines or other towers, respectively, Brown and Johnson couldn’t speculate how many people have been affected.

“Some businesses that lease the lines have redundant paths,” Johnson said. “So, some customers should be OK because they’re using fiber optics from somewhere else.”