Wyo. Stat. § 4-10-411: Modification or termination of trust; proceedings for approval or disapproval.

(a) In addition to the methods of termination prescribed by W.S. 4-10-412 through 4-10-415, a trust terminates to the extent the trust is revoked or expires pursuant to its terms, no material purpose of the trust remains to be achieved or the purposes of the trust have become unlawful, contrary to public policy or impossible to achieve.

(b) A proceeding to approve or disapprove a proposed modification or termination under W.S. 4-10-412 through 4-10-417, or trust combination or division under W.S. 4-10-418, may be commenced by the settlor, a trustee or beneficiary. The settlor of a charitable trust may maintain a proceeding to modify the trust under W.S. 4-10-414.