The county treasurer may deposit in any bank, capital stock financial institution, or qualifying mutual financial institution of the county in which he or she is treasurer in excess of the amounts authorized in section 77-2318 when (1) the depository secures the deposits by giving security as provided in the Public Funds Deposit Security Act and (2) the same is approved by a formal resolution of the county board. Section 77-2366 shall apply to deposits in capital stock financial institutions. Section 77-2365.01 shall apply to deposits in qualifying mutual financial institutions.