A woman who was kidnapped at a Montana rest stop in broad daylight was able to talk with her husband by cellphone several times and even talked with police, but she was dead by the time authorities found her car 325 miles away near Spokane International Airport, Montana authorities said.

Rita Maze, 47, of Great Falls called her husband Tuesday evening and said she had been struck on the head at an Interstate 15 rest stop north of Helena and that she was in the trunk of her car, Lewis and Clark County Sheriff Leo Dutton said Wednesday.

Her husband reported her missing and spoke with her several times as cell coverage allowed, Dutton said.

"She's saying she's kidnapped," Dutton said.

Law enforcement tracked the use of her cellphone to help locate the vehicle. Her car's license plate was captured on a license plate reader near Post Falls, Idaho.

A Helena police officer talked to Maze shortly before she died, Dutton said.

Her body was found in the trunk of her car at 12:30 a.m. Wednesday, Spokane County Deputy Mark Gregory said. The cause of death was not released.

There is a person of interest in the case, Dutton said, and authorities were looking at surveillance video from a convenience store.

The FBI is investigating because interstate travel was involved. A spokeswoman said the agency wasn't releasing any further information, and Lewis and Clark County referred all questions to the FBI.

Maze was a longtime cook at Morningside Elementary School in Great Falls, the Great Falls Tribune reported.