“If Congress consented, then the States were in this respect restored to their original inherent sovereignty; such consent being the sole limitation imposed , by the Constitution,' when given, left the States as they were before, as held by this Court in Poole v. Fleeger, 11 Pet. 209; where, by their compacts became of binding force, and finally settled .the boundary between them; operating with the same effect as a treaty between sovereign powers. .That is, that the boundaries so established and fixed by compact between nations, become conclusive upon all subjects and citizens thereof, and bind their rights; and are to be treated to all intents and purposes, as the true real bound-1 aries.”
See also Garcia v. Lee, 12 Pet. 511, 521; Coffee v. Groover, 123 U. S. 1, 29, 30, 31; Virginia v. Tennessee, 148 U. S. 503, 525.
The rule as applied to the apportionment by judicial decree of the water of an interstate stream was stated in Wyoming v. Colorado, 286 U. S. 494, 508:
“But it is said that water claims other than the tunnel appropriation could not be, and were not, affected by the decree, because the claimants were not parties to the suit or represented therein. In this the nature of the suit is misconceived. It was between States, each acting as a quasi-sovereign and representative of the" interests and rights of her people in a controversy with the other. Counsel for Colorado insisted in their brief in that suit that the controversy was 'not between private parties’ but ‘between the two sovereignties of Wyoming and Colorado’; and this Court in its opinion assented to that view, but observed that the controversy was one of immediate and deep concern to both States and that the interests of each Were indissolubly linked with those of her appropriators. 259 U. S. 468. Decisions in other cases also warrant the conclusion that the water claimants in Colo