WEST GLACIER, Mont. -Glacier National Park officials say they expect the entire length of the Going-to-the-Sun Road to be open to vehicle traffic July 13. A heavy snowpack and an unseasonably cool spring hampered plow crews as they tried to clear the upper section of the road. Park officials say a recent flyover of Logan Pass revealed snowpack that looked more like levels measured in April than June. As of Wednesday, "The Big Drift" snow bank on the pass still towered about 30 feet above the road.

The Big Drift is the result of winter snows and blowing winds. Located east of the Continental Divide along the Going-to-the-Sun Road, this snowdrift can accumulate over 100 feet deep.  Winds push snow up and over the Continental Divide onto a thin ridge of rock (that was formed by glaciers), which is known as the Garden Wall.

In the spring, a helicopter surveys the area in preparation for snow removal of Going-to-the-Sun Road. They use GPS and visual signs to identify potential avalanche risks and to help locate the road, which is completely hidden by snow.

Usually in early April, crews begin removing snow working from both ends of the 53 mile road. The Big Drift is typically reached sometime in late May, and it can take a month to clear that one mile stretch of road.  The crews use explosives and front-end loaders to remove the snow by pushing it over the cliff or hauling it away in dump trucks.  Plowing the entire stretch of road takes about ten weeks.