The National Park Service just turned 100 years old! Celebrate the start of these national treasures’ second century by visiting a park in 2017. During ten days of the year, all National Park Service sites that charge an entrance fee will offer free admission to everyone. If  you are planning on traveling up north across the border then you can also get free admission to Canada’s National Parks year-round.

Mark your calendar for these entrance fee–free dates in 2017:

January 16: Martin Luther King Jr. Day
February 20: Presidents’ Day
April 15-16 and 22-23: Easter and Weekends of National Park Week
August 25: National Park Service Birthday
September 30: National Public Lands Day
November 11-12: Veterans Day Weekend