Scavengers and Thieves

I don't see any harm in picking up arrowheads. People have long scoured the ground looking for arrowheads. This is what they do in the Midwest, in lieu of having relationships or television. I do think that anyone robbing Federal Lands of human remains is a ghoul:
Stepping into the afternoon sun last month, Jeanne Redd and her daughter Jericca walked away from a federal courthouse with probation papers — not prison time — for their role in the theft and illegal trafficking of Indian artifacts.

Some, including one of the Salt Lake City's daily newspapers, expressed frustration that the judge didn't come down harder on the duo from southern Utah.

History, however, says the punishment for the Redds, who pleaded guilty to several felonies, was fairly typical. Despite high-profile arrests and indictments, most people convicted of illegally digging up, collecting and cashing in on artifacts in the United States don't go to prison.
Given the fact that we can discover something important at any given time, with regards to the fossil record or just in general, we cannot have people looting Federal Lands. If you're not on Federal Land, and you find an arrowhead, fine, keep it, it's yours. I think that if you find evidence that the Incas were living in Montana and were riding around on elephants, wearing severed alien heads, well, you should probably tell someone about that.