Wyo. Stat. Ann. § 7-13-201

Except where a term of life is required by law, or as otherwise provided by W.S. 7-13-101, when a person is sentenced for the commission of a felony, the court imposing the sentence shall not fix a definite term of imprisonment but shall establish a maximum and minimum term within the limits authorized for the statute violated. The maximum term shall not be greater than the maximum provided by law for the statute violated, and the minimum term shall not be less than the minimum provided by law for the statute violated, nor greater than ninety percent (90%) of the maximum term imposed.