Tioga Pass is the highest pass in the Sierra, and the last to open, usually. They're still working to sling the snow off and open it for the season.

Few roads traverse the Sierra Nevada, the rocky spine running 400 miles up the state that is home to Yosemite National Park. Mountain passes are typically open by Memorial Day.

The only road through Yosemite, Highway 120, remained closed this week as crews dig out from snows that topped 20 feet and drifted well over 50 feet.

But the serenity of the Sierra Nevada, with birds chirping beneath snow-crested peaks that tower above 12,000 feet, was shaken by the roar and beep of plows, excavators and massive machines carving through 15-foot snowbanks and moving giant blocks of snow. Big snow blowers sent plumes arcing through the air and off the side of the road.

As the Caltrans crew dug the entrance out from the east, a crew from the park was working from the west to clear the road that winds its way to Yosemite Valley, the park's top destination.

Caltrans had begun inching its way up the road more than two months ago when it seemed more like winter. It snowed on and off throughout the spring, with a late-season storm hitting last weekend.

Just to the north of the park, Sonora Pass opened Tuesday. Ebbetts Pass farther north remains closed, said Skip Allum, a Caltrans spokesman. To the south, crews plowed the road over Minaret Summit near Mammoth Mountain ski area.

In Lassen Volcanic National Park, much farther north, deep snow still buries the road that circles the southernmost peak in the Cascade Range. The road is expected to open in early July.

The snowpack presented an additional challenge this year because it was heavily saturated with water. The dense and frozen snow was harder to cut through, heavier to move and broke equipment, Paul Jensen, a Caltrans plow driver, said.