I would like to visit every National Park [2], and possibly the other areas of the US National Park System.

Parks I've already visited:

• Mammoth Cave NP (childhood)
• Mount Rainier NP (2014)
• Rocky Mountain NP (2015)
• Grand Canyon NP (2015)
• Zion NP + Bryce Canyon NP + Arches NP + Canyonlands NP (2017)