I believe it is 50 years in the US. I can't find it on mobile, but I remember reading an article a while back about some simple "john was here" on some anasazi

I believe it is 50 years in the US. I can't find it on mobile, but I remember reading an article a while back about some simple "john was here" on some anasazi petroglyph that hadn't been removed because it was from the late 1800s or early 1900s and was considered historic. https://www.nps.gov/subjects/nationalregister/how-to-list-a-property.htm https://www.nps.gov/subjects/nationalregister/how-to-list-a-...