Barbed wire
https://www.codot.gov/programs/colorado-transportation-matters/statewide-transportation-plans/progress-made
https://www.codot.gov/programs/yourtransportationpriorities/colorado-transportation-matters-old/assets/images/barbed-wire/view
https://www.codot.gov/programs/yourtransportationpriorities/colorado-transportation-matters-old/assets/images/barbed-wire/@@download/image/Barbed wire.jpg
Barbed wire
https://www.codot.gov/programs/colorado-transportation-matters/statewide-transportation-plans/progress-made