Crews feverishly blowing snow off the road in early June as they ready for the first summer visitors
Crews feverishly blowing snow off the road in early June as they ready for the first summer visitors
A dangerous snow removal operation is continuing in areas of Yosemite National Park.

Snow fell as recently as Monday, but a late week heat wave with temperatures increasing by 40 degrees will help the removal of snow in the park and other areas of northern California.

Crews have been working round-the-clock through spring to clear the snow from the roads of the state's highest mountain, which stretches 400 miles.

Mountain passes are typically open by Memorial Day. Though the only road through Yosemite, Highway 120, remained closed at the park's eastern entrance this week as crews dig out from snows that topped 20 feet and drifted well over 50 feet.

A trucking sign peers out of a high snow bank in Yosemite National Park in early June
A trucking sign peers out of a high snow bank in Yosemite National Park in early June
The eastern entrance for the highway which sits atop the state's highest automobile pass is typically closed through May and opens later after a snowy winter. However, park spokesman Scott Gediman said Tuesday there is still no date set for it to re-open.

Getting the snow off the roads that stretch through the Sierra Nevada is treacherous work. Crews use plows, excavators and massive machines carving through towering snowbanks and moving giant blocks of snow.

'It's spooky, it's nerve-wracking... especially when you can't see the road. You're on a big sled,' said Clint Weier, a maintenance superintendent with California Department of Transportation or Caltrans.

Caltrans had begun inching its way up the treacherous road more than two months ago when it seemed more like winter. It snowed on and off throughout the spring.

Workers face a myriad of hazards. Avalanches can crash down the mountains steep slopes taking trees and rocks with them, shutting roads. Melting snow increases the avalanche occurrences. A Yosemite plow driver was killed by an avalanche in 1995.

Operating large machinery like this excavator on the Park's narrow roads can be extremely dangerous
Operating large machinery like this excavator on the Park's narrow roads can be extremely dangerous
Rockslides pose a threat even after workers use explosives and other methods to release snow slides to alleviate the danger. Slides can crush guardrails that are the lone barrier between the road and the drop that plunges hundreds of feet into the east park entrance.

The extreme heat swing will help speed up snow removal but it will pose its own frightening hazards for workers and park revelers alike.

The warmer weather while speeding up snow melt will cause flows to surge in creeks, rivers and streams, according to meteorologist Dawn Johnson of the LA Times.

Showers and thunderstorms may move over the Sierra Nevada on Sunday and Monday.

Yosemite National Park covered in snow (top) versus typical scene in summer (bottom)
Yosemite National Park covered in snow (top) versus typical scene in summer (bottom)