RSA 29:1 Duties.

I. The county treasurer shall have custody of all moneys belonging to the county, and shall pay out the same only upon orders of the commissioners. The county treasurer shall deposit the same in participation units in the public deposit investment pool established pursuant to RSA 6:45, or in federally insured banks authorized to accept deposits under RSA 6:8, I and I-a. In addition, funds may be deposited in federally insured banks outside the state if such banks pledge and deliver to a third party custodial bank or the regional federal reserve bank collateral security for such deposits of the following types:
(a) United States government obligations,
(b) United States government agency obligations; or
(c) Obligations of the state of New Hampshire in value at least