Wyo. Stat. § 41-12-502: When binding; notice of ratification.

Said compact shall not be operative unless and until the same shall have been ratified by the legislature of each of the said states and approved by the congress of the United States. The governor of Wyoming shall give notice of the ratification and approval of said compact by the thirtieth Wyoming legislature to the governor of the state of Idaho and to the president of the United States.