The Rio Grande Compact was an interstate agreement to apportion equitably the water of the Rio Grande among Colorado, New Mexico, and Texas. A preliminary compact of February 12, 1929, provided for stream-gauging stations, for construction of a reservoir in Colorado, and for equitable dividing of the water of the river pending the signing of a permanent compact. The compact was signed at Santa Fe, New Mexico, on March 18, 1938, approved by the state legislatures, and approved by Congress on May 31, 1939. The table worked out provided for Colorado and New Mexico to deliver water in accord with a formula based upon the flow of the Rio Grande and its tributaries at designated gauging stations above the state lines. A Rio Grande Compact Commission, consisting of one representative from each state, was established, the state engineers of Colorado and New Mexico serving ex officio and the Texas commissioner being appointed by the Texas governor. The United States designates a representative to sit with the commission.