The pension trust funds must be managed as follows:
(1) The board is the trustee of all money collected for the retirement systems and has exclusive control of the administration of the pension trust funds except as otherwise provided by law.
(2) The department shall deposit in the state treasury all amounts received by the board as provided in this chapter.
(3) Except as provided in chapter 3, part 21, of this title, the state treasurer is custodian of the pension trust funds, subject to the exclusive control of the board for administration and the board of investments for the investment of the funds.