C.R.S. § 37-61-102

That said compact shall not be binding and obligatory on any of the parties thereto unless and until the same has been approved by the legislature of each of the said states and by the congress of the United States, and the governor of the state of Colorado shall give notice of the approval of said compact by the general assembly of the state of Colorado to the governors of each of the remaining signatory states and to the president of the United States, in conformity with article XI of said compact.