Marias Pass is a mountain pass in the Rocky Mountains in the western US state of Montana. Lying on the southern border of Glacier National Park, it is traversed by US Highway 2 and by the BNSF Hi-Line Subdivision. The pass is the lowest crossing of the Continental Divide between Canada and central New Mexico , and is the northernmost pass in the US open to automobile traffic year-round.

Glacier National Park is an American national park located in northwestern Montana, on the Canada–United States border, adjacent to Waterton Lakes National Park in Canada—the two parks are known as the Waterton-Glacier International Peace Park. The park encompasses more than 1 million acres (4,000 km2) and includes parts of two mountain ranges, more than 130 named lakes, more than 1,000 different species of plants, and hundreds of species of animals. This vast pristine ecosystem is the centerpiece of what has been referred to as the "Crown of the Continent Ecosystem," a region of protected land encompassing 16,000 sq mi (41,000 km2).