While I've been gone

This month has been extremely busy with trips to Oregon, Colorado and Missouri and I'm just now working on getting life back in order. Until I figure out what (if anything) I'll have to say from these trips, here is a little gem from my time in Missouri. This is a sign at a state park we stayed at; what does it mean?

When I saw it I had just realized the camp ground had no cell phone coverage and so I thought that it was pointing the way to a magic location where cell phones would work. It wasn't.