The Rio Grande Compact is an agreement signed in 1938 between Colorado, New Mexico, and Texas to equally apportion and administer the waters of the Rio Grande River. Approved by Congress in 1939, the Compact includes provision for a Commission made up of the State Engineers from each of the three states (or their designees), and a fourth, federal appointee who serves as Chair. The Commission publishes an annual report, and our library has recently posted online the full set of these reports going back to the first in 1939. You can read the full Compact on the Colorado State Engineer’s website. The State Engineer’s Office has also published a report summarizing Colorado’s interstate compacts, A Summary of Compacts and Litigation Governing Colorado’s Use of Interstate Streams, available online from our library.