RCMP say all five of the cars on the Canadian Pacific train that left the track early Saturday morning were empty and that no chemicals were spilled.
There were no reports of injuries.
Railway spokeswoman Breanne Feigel says the derailed cars last contained sulphur.
Feigel says there's no word yet on what caused the train to derail.
She says the derailment has been cleared and the track is now open.
"We take all incidents like this quite seriously," Feigel said, noting that police, transportation officials and Parks Canada staff were all notified.
Police say the incident happened while the train was moving slowly past a transfer station.
They say a mechanical issue with one of the cars is thought to have caused the derailment, and that there was no indication of criminal activity.