Driving across the US west, you can’t help but notice how every bit of land is cordoned off with barbed wire or fences. Doesn’t matter if it’s in the middle of emply plains or uninhabited mountains. "Private property" and "no trespassing" signs abound.
Hardly "every bit". The federal government owns more than half of the land west of the Rockies [0], and most of that (e.g. US Forest Service and BLM land) is free to roam over. Much of it you can camp anywhere you want, too.
You do have to ask permission of the landowner to hike/camp on their property. But with the size of some of the cattle on the land (I'm thinking of Texas Longhorns) and the presence of common predators/pests like feral hogs and coyotes, it's not always safe to just wander around.
There's also the water issue. If you run out of water in the west while on your hike/tramp, you're in life-threatening trouble. And there's often no cellular service.
