The National Park Service is offering free admission on select days in 2017 to celebrate its 101st year. For their more than 400 parks, regular admission ranges from $3 to $30.

Here in Wyoming we can enjoy:
Bighorn Canyon National Recreation Area
Devils Tower National Monument
Grand Teton National Park
Yellowstone National Park

A list of all National Parks is available here.

The next fee free days will be April 15-16 and April 22-23: Weekends book-ending National Park Week