Wyo. Stat. § 24-2-112
The legislature of the state of Wyoming assents to the provisions of the act of congress approved July 11, 1916, entitled "an act to provide that the United States shall aid the states in the construction of rural post roads, and for other purposes," together with all acts and legislation, amendatory or supplementary, or which shall grant or authorize aid for the construction, improvement, maintenance or repair of public roads or highways. The transportation commission is authorized to enter into all contracts and agreements with the United States government relating to the construction and maintenance of roads under the provisions of the act or acts of congress to submit the scheme or program or construction or maintenance as may be required by the federal highway administration and to do all other things necessary fully to carry out the cooperation contemplated and provided for by the act or acts, for the construction or improvement of highways under the act, the good faith of the state is pledged to make available funds sufficient to equal the sums apportioned to the state by or under the United States government during each of the years for which federal funds are appropriated by section 3 of the act and to maintain the roads so constructed with the aid of funds appropriated and to make adequate provisions for carrying out maintenance. Cooperative agreements under the provisions of the act shall be entered into with the federal highway administration only by the commission, but may be for the construction or improvement of either a state highway or a county road. If the road to be improved under such cooperative agreement is a state highway, the state's share of the expense shall be borne entirely by the state; if the highway to be improved or constructed under such cooperative agreement is not a state highway, the state's share of the cost of the work shall be divided between the state and the county upon such basis as the commission shall determine, and before an agreement is entered into with the federal highway administration the county must furnish the right-of-way and shall have entered into an agreement with the commission whereby it shall agree to pay its share of the cost and to pay the cost of all subsequent maintenance, work which shall be performed by and under the supervision of the director of the department of transportation, and the county also shall pay into the state highway fund its share of the estimated cost of the construction.
W.S. 24-2-112