A sign like this was placed at the east end of Portland's Ross Island Bridge in 1961.  I saw it on my way to work at Tektronix, but it didn't register in my brain.   It was removed.  Another was put up in it's place.  It made the front page of The Oregonian this time.  This is when I remembered the story about Billy Goat Gruff.

     We did pass through some rather large unpopulated areas, and did see a warning sign, or two, about the distance to the next services.