Wyo. Stat. § 9-4-817

(a) To the extent they are not otherwise invested, the monies collected and held by a treasurer of a political subdivision, municipality or special district within this state shall be deposited in banks or credit unions which qualify as depositories for public monies as specified in W.S. 9-4-803(a).

(b) In depositing the monies in the financial institutions authorized by subsection (a) of this section, the treasurer shall select the institution:

(i) Repealed By Laws 1996, ch. 112, § 3.

(ii) Designated as a depository by the proper governing board.

(c) The deposits made pursuant to this section shall be made to the extent that they are:

(i) Fully insured by the Federal Deposit Insurance Corporation or the national credit union share insurance fund, whichever is applicable; or

(ii) Secured, in accordance with this article, by a pledge of collateral or the furnishing of a surety bond.

(d) Any bank, savings and loan association, federal savings bank or credit union, located in the state, may apply to keep the monies upon the following conditions:

(i) All deposits are subject to payment when demanded by the proper treasurer on his check, order or demand, except that all funds deposited on time deposit, open account shall be withdrawable, under W.S. 9-4-809;

(ii) All funds deposited in a savings deposit account shall be withdrawable upon demand provided that the bank, savings and loan association or credit union may at any time require giving of notice in writing of an intended withdrawal of thirty (30) days before a withdrawal is made;

(iii) Interest shall be paid upon the amount deposited which constitutes a time deposit, open account;

(iv) All deposits are also subject to regulations imposed by law.