Ranger-led Activities - Glacier National Park (U.S. National Park Service) A wildlife talk NPS/Tim Rains. Bring water with you! The mountains can get very hot in the summer. Surface water in the park may be unsafe to drink. Join us in Summer! Our scheduled activities include a variety of ranger-led programs, from easy walks and evening talks, to all-day hikes, boat tours and Native America Speaks programs. PDF versions of the schedule for June, July, August, and September are available online. Schedules are made available about one week before the start of each month. Programs start mid-June and generally conclude at the end of September.