Operating Hours & Seasons - Glacier National Park (U.S. National Park Service) Going-to-the-Sun Road runs through the middle of the park and provides access to many locations and activities. Ten miles of Going-to-the-Sun Road (West Glacier to Lake McDonald Lodge) are maintained throughout the year providing access to winter recreation opportunities at the head of the lake. Glacier National Park is open every day of the year and visitors can enter the park at anytime. Winter weather tends to dictate when most visitor facilities open and close. Generally from late May to early September, facilities are open to welcome summer visitors.