The National Park Service has released the list of free entrance dates for all U.S. national parks for 2016.  If you are thinking of visiting a U.S. national park in 2016, you might want to mark these dates on your calendar.

Normally, 127 of the 409 U.S. national parks charge an entrance free.  However, there are a few days a year where all the national parks offer free entry.

The entrance fee–free dates in 2016 are listed on the National Park Service website as follows:

• January 18: Martin Luther King Jr. Day
• April 16 through 24: National Park Week
• August 25 through 28: National Park Service Birthday
• September 24: National Public Lands Day
• November 11: Veterans Day

Here is the list of the 127 national parks that are waiving the entrance fee. The rest of the parks offer free entry year round.