Yosemite National Park - Tioga and Glacier Point Roads Plowing Update (U.S. National Park Service)

The Tioga Road will open on May 20, 2009, at 10 am, conditions permitting.

The Glacier Point Road opened on May 5, 2009.

The Mariposa Grove Road opened on April 17, 2009.

Once plowing of the Tioga Road is completed, additional work must be completed before the road can safely be opened.

Factors affecting plowing operations:

Avalanche zones (26 potential areas). The Olmsted Point avalanche zone requires a lot of work, including application of charcoal over the snow to help with melting and blasting the snow slab to make it safer for personnel.
Heavy snow pack slows the whole operation.
Trees that have fallen across the road and been buried in the snow. These can cause substantial damage to the equipment and result in a stop to all operations until they're cleared.
Rock slides buried by the snow. These can cause substantial damage to the equipment and result in a stop to all operations.
Snow storms during the opening require a stop to Tioga Road operations and in order to plow and sand the park roads.
Road repairs and ditching and brushing operations once snow has melted back enough.

Near Raisin Creek.

Watch a 3.5-minute video about plowing of the Olmsted Point avalanche zone. [7.7 MB Quicktime Movie (MOV)]