A downed power line is responsible for forcing the Mt. Ashland Ski Area to close yesterday. A fallen tree on Old Highway 99 knocked out power to an estimated 302 Pacific Power customers. Power had been restored to most customers by 9:40 a.m. The outage also affected Callahan's Mountain Lodge. Mt. Ashland is closed on Tuesdays and Wednesdays, but is expected to reopen on Thursday morning.