The law in many states now allows a landowner to mark the edge of their property with purple paint on the trees to be the same as posting it no hunting/fishing/trespassing. We have the proper paint color, specially formulated for use on trees and to stay visible for a long period out in the weather.
Comes in 12 ounce spray cans, made 100% is the USA!
Here is the law in NC, your state may vary.
The owner or lessee of the property may place identifying purple paint marks on trees or posts around the area to be posted. Each paint mark shall be a vertical line of at least eight inches in length, and the bottom of the mark shall be no less than three feet nor more than five feet from the base of the tree or post. The paint marks shall be placed no more than 100 yards apart and shall be readily visible to any person approaching the property. For the purpose of prohibiting fishing, or the taking of fish by any means, in any stream, lake, or pond, it shall only be necessary that the paint marks be placed along the stream or shoreline of a pond or lake at intervals of not more than 100 yards apart."