N.H. Rev. Stat. Ann. § 201-E:3

Any property held by a museum within the state, other than by terms of a loan agreement, that has been held for 5 years or more and has remained unclaimed shall be deemed to be abandoned. Such property shall become the property of the museum, if the museum has given notice pursuant to RSA 201-E:5 and no assertion of title has been filed for the property within 90 days from the date of the second published notice.