N.H. Rev. Stat. § 227-C:11
Information which may identify the location of any archeological site on state land, or under state waters, shall be treated with confidentiality so as to protect the resource from unauthorized field investigations and vandalism. Toward this end, state agencies, departments, commissions, institutions and political subdivisions, permittees and private landowners with preservation and conservation agreements shall consult with the commissioner before any disclosure of information to insure that the disclosure would not create a risk to the historic resource or that it is done in a manner to minimize the risk. Such information is exempt from all laws providing rights to public access. Disclosure for the public record for tax assessment, transfer, sale or other consideration of the property shall receive careful consideration to minimize the risk to the resource.
RSA 227-C:11
RSA 227-C:17. 1981, 504:5. 1985, 345:3.