March 15, 2023 - Caltrans officials reported that on March 7, Caltrans initiated an avalanche control operation on the hillside along U.S. 395 between Lee Vining and State Route 167. Using a helicopter, Caltrans dropped approximately 20 small explosives attempting to trigger an avalanche.

The snowpack proved to be too firm, and no avalanches were recorded as part of the operation. With the hillside deemed safe, emergency work began on March 8 to begin clearing the avalanches from U.S. 395.

Beginning Thursday, March 9, a warmer atmospheric river moved into the region, bringing with it rain and higher snow levels. Emergency work had stopped before the storm arrived, and on March 12, Caltrans initiated another avalanche control operation using its Gazex system.

This operation did trigger an avalanche that brought a significant amount of heavy and wet snow down onto U.S. 395 south of previous avalanches but within the current closure. With more storms in the forecast, Caltrans will perform additional avalanche mitigation operations this week before the emergency work can resume. Once work has restarted, it will be at minimum two weeks before the highway can reopen in a limited capacity.

Source & photo: Caltrans