## Facts

- Morris, a Wyoming citizen, claimed a prior appropriative right to waters of Sage Creek, a small nonnavigable stream flowing from Montana into Wyoming and then through connected river systems back into Montana.
- Morris sued Montana users (Bean and others, Montana citizens) to enjoin upstream diversions in Montana that allegedly impaired Morris’s downstream Wyoming appropriation.
- Howell, also a Wyoming citizen, intervened asserting an additional downstream Wyoming appropriation.
- The region historically applied the prior-appropriation doctrine rather than common-law riparian rights.
- The lower courts found priority and amounts as follows: Morris—100 inches (miner’s measurement), priority April 1887; Howell—110 inches, priority August 1, 1890; Bean—later uses beginning about 1893.

## Issues

1. Whether a water appropriation validly made under Wyoming law on an interstate, nonnavigable stream can be enforced against later conflicting diversions by private parties in Montana, absent contrary legislation.

## Decision

- The Supreme Court affirmed the decree protecting Morris’s and Howell’s earlier Wyoming appropriations against Bean’s later Montana diversions.
- The Court applied a presumption that, absent legislation to the contrary, each state along an interstate stream allows water rights to be acquired from outside the state on the same terms as from within.
- Because prior appropriation historically governed in both states, and the challenged Montana uses were junior in time, the earlier Wyoming appropriations controlled.

## Legal Principles

- For interstate, nonnavigable streams, and absent contrary legislation, courts presume each state recognizes water rights initiated in another state to the same extent it recognizes rights initiated within its own borders.
- In a prior-appropriation system, priority in time determines priority in right, including across state lines on a shared watercourse when the system is treated as continuing in the region.
- Private upstream diversions in one state may be enjoined when they impair senior appropriative rights lawfully acquired downstream in another state under a commonly recognized appropriation regime.

## Conclusion

The Court held that senior Wyoming appropriative rights on an interstate, nonnavigable stream were enforceable against junior Montana diversions, relying on a presumption of interstate recognition of comparable water rights absent legislative departure and on the controlling rule of priority.


Bean v. Morris, 221 U.S. 485 (1911)