A fatal crash is being investigated near the intersection of Mill Creek Road and Custer Frontage Road.
A male in his early 20s lost control of his vehicle, overcorrected, went off the road and rolled, said Montana Highway Patrol Ben Panas.
The call came in at 5:56 a.m., according to MHP records.
The driver, who appears to have been traveling alone, was not wearing a seatbelt and was ejected, he said.
Whether speed and alcohol were contributing factors to the crash are being investigated.