To celebrate its centennial year, the National Park Service is offering an extended schedule of fee-free days - 16 in total - including nine straight days of free access to America's parks and monuments during National Park Week, April 16 to 24, 2016.

Admission will also be waived Aug. 25-28 (National Park Service's birthday), Sept. 24 (National Public Lands Day) and Nov. 11 (Veterans Day).

Click here for a look at the eight national parks and monuments in Colorado.