Greyhound spokesman Timothy Stokes said the bus was carrying 42 passengers. He said just one person was hurt.
He said the bus was on a trip from Vancouver to Prince George when the accident happened shortly before 1 a.m. near Logan Lake.
"No serious injuries reported. All passengers were transported to a nearby hospital as a precaution and once checked out by hospital staff they will continue on their travels," Stokes said.
RCMP Const. Robert Drake said the bus driver was trying to avoid hitting another vehicle when the accident occurred.
"It appears the Greyhound bus had gone off the road, rolling onto its side down an embankment as it was avoiding another vehicle which was broken down in the area at the time," he said.
"The passengers were extracted through the front windshield as the passenger door to the bus was not accessible."
Drake said weather may have been a factor in the crash.
"The investigation is on-going, however, there was a heavier snowfall in the area at the time with large amounts of snow on either side of the road."