The following press release was published by the U.S. Department of the Interior, National Park Service on June 14. It is reproduced in full below.

Between 1926 and 1927, laborers constructed this tunnel on the west side of Going-to-the-Sun road. It is an engineering marvel, taking vehicles through a steep cliff, while featuring two observation windows to view Heavens Peak and McDonald Creek.

Glacier National Park

Source: U.S. Department of the Interior, National Park Service