Odd things you find while roaming around in the mountains

On our last trip I was running around in our Rhino one day looking for other camp sites when I saw this sign.

So I drive down the road and I see a few camp sites and the I come around a corner through the trees and I see this.

As you can see this is not a camp spot, trailer storage for who, USFS employees ?  Or are they confiscated trailers from people who left them to long or just a place so people can leave there trailer on the mtn till they come back.

There are some oldies here and that's a lot of license plates.