TransAlta says its crews are working to restore electricity to the two communities following an incident at its Cascade hydro power facility in Banff National Park.
The company says it expects the repair job will take a number of hours.
Hugo Shaw, TransAlta's Executive Vice-president of Operations, says it appears water that needed to be released from the Cascade facility got into a transformer causing it to fail.
A loud noise was reported when the transformer blew, but there's been no word of any injuries.
Shaw said in release issued early Sunday morning that water backed up along the Trans-Canada highway next to the facility, forcing the closure of the highway between Banff and Canmore.
He said work was underway to lower water levels so repair crews could get into the Cascade facility, and to help get the highway re-opened.
Note to readers: Fixes typo in 1st para, ADDS Business index