- The "Big Drift” is a 50 - 80 feet snow drift that generally covers a one mile portion of the Going To The Sun Road every winter.
- Removal can require more than one month of plowing.
- Created when warm Pacific air hits cooler, drier air, dumping snow onto the eastern slope of The Garden Wall.
A seasonal obstruction and plowing challenge for Glacier National Park workers, "The Big Drift" is a mighty snow drift that forms every winter, blanketing roughly a one mile stretch of the Going To The Sun Road under 50 - 80 feet of snow.
Situated east of Logan Pass, full access to the Going To The Sun Road is contingent upon removal of the "Big Drift." This impressive natural feature is created when west winds push warm, wet air over the Continental Divide where it meets cooler, drier air, spilling large quantities of snow onto the eastern slope of the popular Glacier arête known as The Garden Wall.
Going To The Sun Road plowing begins in early April, however “The Big Drift” is generally not reached until late May.
Once reached, the “Big Drift” removal process:
- starts with a helicopter survey, gauging avalanche hazards and approach.
- is handled by plows, loaders, and other heavy equipment, and explosives when necessary.
- usually takes one month to clear.
- generally covers a one mile stretch of the Going To The Sun Road, and can be upwards of 30 meters (100 ft) in depth.
Early April - early June.
The Glacier National Park Service “Where Are The Plows?” website keeps travelers abreast of daily snow plowing progress on The Going To The Sun Road. www.nps.gov/applications/glac/gttsroadplow/gttsroadplowstatus.cfm.
Going To The Sun Road 2010 tentative opening date: June 18