The national parks of the United States are often compared to, and indeed inspire, works of art. In fact, the USGS has been regularly contributing new and updated works of art for the national parks—maps.

A Champagne-doused celebration of an ultra-marathoner's record run up the Appalachian National Scenic Trail that finished atop Mount Katahdin in Baxter State Park in Maine didn't set well with Jensen Bissell, the state park's director. He has suggested moving the trail out of the park, in part because of growing crowds of hikers and their celebrations.

Located roughly mid-way between New York City and Philadelphia, the Delaware Water Gap National Recreation Area is a verdant, mountainous oasis cut by a cooling river that attracts millions every year, with most coming during the summer months to relax and gain a bit of respite from the region's notorious humidity. Those millions, though, can be oppressive when squeezed too closely together.

There are more than a few experiences of a lifetime to be had in the National Park System, but arguably two right at the top of anyone's list would be a raft trip on the Colorado River through Grand Canyon National Park, and a multi-month sojourn along the Appalachian National Scenic Trail.