In Idaho, Orange Paint Means ‘No Trespassing’
Did you know that in Idaho, the color orange means "No Trespassing" regardless of whether or not there is a posted sign?
If you come across fence posts, with the top 18 inches or more painted orange, you should get out. You're on private property and they don't want you there.
I've lived in Idaho for most of my life and had no idea, uniI I saw this information about states that use various paint colors to identify private property lines. In Texas, they use purple. In Idaho, orange is the color that means "Keep out!"
They say that the paint can be used to complement or even replace signs in areas where things inclimate weather can either damage signs or even blow them over.
...posted with a minimum of one hundred (100) square inches of fluorescent orange, bright orange, blaze orange, safety orange or any similar high visibility shade of orange colored paint except that when metal fence posts are used, a minimum of eighteen (18) inches of the top of the post must be painted a high visibility shade of orange.
If you're out and about and come across fence posts, with the top 18 inches or more painted orange, you should get out. You're on private property and they don't want you there.