Spring snow plowing is under way in Glacier National Park, with crews expecting to encounter deep snow in some areas.

Automated snow measuring sites at Flattop Mountain and Many Glacier show snow water equivalents from 20 to 40 percent above normal.

Last week, a snow survey crew measured 100 inches of snow on the east side of Going-to-the-Sun Road at Siyeh Bend and 140 inches of snow nearby at 7,500 feet.

Crews plowed near Fish Creek in the Apgar area and one lane on the Camas Road starting last week. The Camas Road and the Inside North Fork Road will be allowed to melt out before they are opened.

Plowing on Going-to-the-Sun Road started April 1 beyond Lake McDonald Lodge. Crews were encountering 12 to 36 inches of snow with six inches of ice on the road surface. One the road is cleared beyond Avalanche Creek, the park’s road construction contractor will resume rehabilitation work on the road along Upper McDonald Creek.

Because of rehabilitation work that requires closure of both lanes, the earliest possible opening of Sun Road in its entirety would be June 17, depending on how plowing progresses on the road’s higher elevations.

Once road crews are working at higher elevations, the park typically allows hikers and bikers to travel beyond Avalanche Creek on the west side and Jackson Glacier Overlook on the east side.

“There will be great recreational opportunities in Glacier this spring,” Superintendent Chas Cartwright said. “Visitors can hike or bicycle beyond vehicle closures when crews are not working: exact distances will depend on plowing crew locations and construction activity.”

On the east side, plowing started on the Chief Mountain Road and the Two Medicine Road in mid-March. Instead of encountering three-foot drifts as they do most years, the crews were plowing through drifts up to eight feet deep.

This week’s plowing efforts on the east side are focused on the Many Glacier Road, where crews are encountering drifts over 10 feet deep. The Many Glacier Road will not open to vehicles until the third weekend of April at the earliest, to reduce impacts on wildlife that are concentrated in winter range areas.