Wyo. Stat. § 19-9-103: Manner of calling for duty.

(a) Officers and enlisted personnel may be called for duty by any of the following means:

(i) By stating the substance of the order or by reading it to him in person or over the phone;

(ii) By radio or television communication;

(iii) By leaving a copy of the order with a person over the age of fourteen (14) years at his last known place of residence or business; or

(iv) By sending a copy of the order or the substance of the order by electronic means to him at his last known place of residence or business or by United States mail to his last known address.