R.I. Gen. Laws § 42-45.1-10: State archaeological landmarks.

The state historical preservation commission may publicly designate an archaeological site or underwater historic property as a “state archaeological landmark”; provided that no site shall be so designated without the express written consent of the owner if it is on privately owned land. Upon designation of an archaeological site, the owners and occupants of each designated state archaeological landmark shall be given written notification of the designation by the commission. Once so designated, no person may conduct field investigation activities, or exploration or recovery activities in the case of an underwater site, without first securing permission from the commission and the express written consent of the landowner. The commission may remove its designation of state archaeological landmark from any site if it deems the site no longer has significance.