Pick signs that back up Idaho laws! Idaho statue states that unless there is permission from the owner, or the owner’s agent, anybody who enters upon property of another person where a “No Trespassing” sign is posted is considered willful trespassing. Therefore, turn to Private Property: No Trespassing signs with Idaho's law imprinted on it in 3M ink. The signs will last for years outdoors thanks to their durable aluminum composition. Note: Idaho requires that signs are spaced at intervals of no less than one notice per 660 feet along such real property. Questions? Call our Live Help listed above.