Snow Plows on the Highways

by Tom Stienstra
San Francisco Chronicle - April 24, 2003

The giant rototiller-like snow removal machines are out on the mountain highways this week, with CalTrans hoping to clear Sierra passes and open the roads for vacationers prior to Memorial Day Weekend.

CalTrans predicted that Ebbetts Pass (Highway 4), Sonora Pass (Highway 108) and Tioga Pass (Highway 120) would be cleared and open by May 23. A traditional early opener, the June Lake Loop (Highway 158) in the eastern Sierra, is already cleared and open.

Many vacationers hinge their Memorial Day plans on Tioga Pass in Yosemite, the dramatic route that passes Tuolumne Meadows, and then drops into Lee Vining Canyon to the east near the foot of Mono Lake. As of Tuesday, snowplow operators are clearing about two miles per day, and have gained 11.8 miles from the Crane Flat Gate.

The average snow depth on the road here is six feet, with drifts as high as 10 feet. Plow operators say the snow is extremely dense, with recent storms adding to the load. In the past four years, Tioga Pass has been opened to traffic by Memorial Day. In 1998, however, it wasn't cleared until July 1.

The snow is too dense, with an ice pack sub-layer, to be plowed by blades. Instead, massive machines that look like spinning rototillers chip away at the ice block on the roads, and then send ice chips flying through a chute and clear of the road.

Outdoor notes of note:

The Yosemite Falls parking lot was closed permanently Wednesday; it will be replanted with native plants and converted in the coming year to a picnic site and informal seating area . . . North Pines Campground, set along the Merced River in Yosemite Valley, opened this week . . . A highlight of Earth Day celebrations on Tuesday was a tour of future project sites in Yosemite Valley, with the tour in the park's new hybrid diesel/electric bus.