Glacier National Park is an American national park located in northwestern Montana, on the Canada–United States border, adjacent to the Canadian provinces of Alberta and British Columbia. The park encompasses over 1 million acres (4,000 km2) and includes parts of two mountain ranges (sub-ranges of the Rocky Mountains), over 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 square miles (41,000 km2).
Glacier National Park is open every day of the year and visitors can enter the park at anytime. It goes without saying though, that the seasons are vastly different, and weather conditions dictate when visitor facilities open and close.
The most popular season is summer, from around late May to early September, when all facilities are open and most of the park is accessible.