Going-to-the-Sun Road is a scenic mountain road in the Rocky Mountains of the western United States, in Glacier National Park, Montana.

The road stretches 50 amazing miles (80 km) reaching a maximum elevation of 6,646 ft (2,026 m) at Logan Pass. Construction began in 1921 and was completed in 1932 with formal dedication on July 15, 1933. The road is the first to have been registered in all of the following categories: National Historic Place, National Historic Landmark, and Historic Civil Engineering Landmark. [source]

According to Wikipedia, the road is one of the most difficult roads in North America to snowplow in the spring. Up to 80 feet (24 m) of snow can lie on top of Logan Pass and the road takes about ten weeks to plow, even with equipment that can move 4000 tons of snow in an hour. [source]

To plan your adventure to Going-to-the-sun Road, visit the official National Park Service page.