Very active day in the Salt Lake mountains - Avalanche reduction work at the resorts resulted in many avalanches breaking mid pack and to the ground, breaking sympathetically to other triggered avalanches. The avalanches were triggered by both ski cuts and explosives, and unpredictable. Many were running long distances and some of these were large enough to break a few trees or bury a car. All elevations on the northerly facing slopes were active, including elevations below 9000 ft.