Wyo. Stat. § 31-18-204: Exemptions.

(a) The provisions of W.S. 31-18-203 through 31-18-208 do not apply to mobile machinery:

(i) Owned by the United States, the state of Wyoming or any political subdivision thereof;

(ii) Which is an implement of husbandry;

(iii) Currently registered under W.S. 31-2-201 or 31-18-201;

(iv) Being transported from a point outside this state through this state or for delivery or repair in this state;

(v) Held for sale by a person engaged in the business of selling mobile machinery;

(vi) Used in the extraction or production of bentonite, coal, trona or uranium and owned by the producer;

(vii) Used exclusively for the drilling of wells;

(viii) Brought into the state for a period not to exceed seven (7) calendar days to demonstrate the operation of the mobile machinery to prospective buyers.