Ancient cultures left marks on the land in the New World, as is evident in many cultural heritage areas, and is visible in particular in desert environments where plants haven't concealed the lines and shapes. Parks tend to be situated in the center of cultural landscapes so the "best" is preserved, but you can examine the landscape outside of parks and see the same features extend for many miles.

The colonial history, marks left by migrants from around the world, is much more recent, but they built walls of stones at the edges of fields and planted hedges here also. In places where agribusiness hasn't moved in to manage large swaths of land, those lines are still visible, and still charming to humans and attractive to wildlife.

There are also windfarms in the more open and windy parts of the U.S. We're getting used to the look of them, like Martian craft in the War of the Worlds marching across the landscape.