W.S. 39-11-103 Imposition.
(a) Taxable event. The following shall apply:
(i) Property subject to taxation. All property within Wyoming is subject to taxation as provided by this act except as prohibited by the United States or Wyoming constitutions or expressly exempted by W.S. 39-11-105;

W.S. 39-11-105(a)(xi)
(xi) Personal property held for personal or family use excluding mobile homes required to be titled under W.S. 31-2-501 through 31-2-508;

W.S. 39-13-103 (b) (i) (A) All taxable property shall be annually listed, valued and assessed for taxation in the county in which located and in the name of the owner of the property on January 1;

W.S. 39-13-103 (b) (i) (B)   All taxable personal property brought, driven or coming into Wyoming, or acquired, after the assessment date and prior to December 31 which remains in Wyoming at least thirty (30) days and has not been regularly assessed for taxation in any other Wyoming county is subject to and shall be assessed for all taxes levied in the county in which the property is located for that calendar year except as hereafter provided. Property subject to this paragraph brought, driven or coming into Wyoming, or acquired, after March 1 is subject to taxes only for the proportionate part of the year remaining, computed to the closest full month.

W.S. 39-13-103 (b) (v)   Except as provided in chapter 14 of this title, annually, commencing on January 1, the county assessor or deputy assessors as provided by W.S. 39-13-102(a) shall obtain from each property owner or person having control of taxable property in the assessment district for which they were appointed, a full, complete and detailed statement of the amount of the taxable property owned by or subject to the control of the property owner. If a property owner fails to provide a listing of personal property owned by him or under his control by March 1, unless an extension is granted from the assessor in writing, the assessor shall issue an assessment of personal property from the best information available. The county assessor shall extend the date for listing personal property from March 1 to April 1 upon written request of the property owner provided the written request is made not later than February 15. The county assessor or his deputies or any representative of the department may examine any property. The county assessor or his deputies shall enter the fair market value of the property for taxation on the assessment roll. The owner, or his agent, shall make and subscribe the following oath:

"I, ...., the owner of (or agent, etc., as the case may be) do solemnly swear (or affirm) that the above and foregoing listed property is a full, true, correct and complete list of all property owned by me or under my control as agent or otherwise, and that I have not failed or neglected to list for taxation for the year ...., all property of which I am the owner or of which I have control as agent, guardian, administrator or otherwise, in the county of ...., State of Wyoming, and that I have not connived at any violation or evasion of the requirements of law in relation to the assessment of property for taxation.";