Historical Highway Markers By Dr. Leif Tapanila & Peter Pruett Published January 11, 2024 at 6:00 AM MST Listen • 29:57 Ways To Subscribe Apple For this episode of The Nature of Idaho, join hosts Dr. Leif Tapanila and Peter Pruett as they discuss road signs with former Idaho State Historian Keith Peterson. Trivia Question: When did the Historical Highway Markers start in Idaho?Trivia Answer: The 1950s