Wyo. Stat. Ann. § 21-3-109
(a) A vacancy shall have occurred in the membership of any board of trustees of any school district if any member:
(i) Dies;
(ii) Resigns;
(iii) Becomes a nonresident of the school district;
or
(iv) Becomes a nonresident of the trustee residence area from which elected in those districts subdivided into trustee residence areas.