Upper Missouri River Basin Compact

Upper Missouri River Basin Compact
Name	Upper Missouri River Basin Compact
Date signed	1949
Location signed	Washington, D.C.
Parties	Montana, North Dakota, South Dakota, Wyoming
Ratified by	United States Congress
Effective	1950
Related legislation	Missouri River Compact (Lower)

Contents

Upper Missouri River Basin Compact The Upper Missouri River Basin Compact is a multistate agreement allocating waters of the upper Missouri River watershed among Montana, North Dakota, South Dakota, and Wyoming. Negotiated in the late 1940s and approved by the United States Congress, the Compact interfaces with federal statutes such as the Water Resources Development Act and interacts with agencies including the Bureau of Reclamation, the United States Army Corps of Engineers, and the Environmental Protection Agency. It complements interstate compacts like the Colorado River Compact and accords among states such as the Great Lakes Compact.

Background and Purpose

The Compact emerged from competing claims tied to hydrologic features including the Missouri River, the Yellowstone River, the Milk River, and the Big Horn River, and from precedents set by the Republic of Texas-era water claims and Supreme Court decisions like Kansas v. Colorado (1907). It sought to prevent interstate conflict similar to disputes seen in the Colorado River Basin and in litigation such as Nebraska v. Wyoming. Influences included policy debates in the U.S. Congress and planning by the Interstate Commerce Commission and the National Resources Committee. The Compact’s purpose aligned with flood control projects of the Pick-Sloan Missouri Basin Program and reservoir development at sites such as Fort Peck Lake, Garrison Dam, and Boydell Dam.

Member states are Montana, North Dakota, South Dakota, and Wyoming. Governance mechanisms rely on a commission model similar to the Colorado River Commission and the Columbia River Basin Commission, composed of gubernatorial appointees and state engineers who coordinate with the Secretary of the Interior and the United States Geological Survey. Meetings reference rules of procedure akin to those adopted by the Atlantic States Marine Fisheries Commission and the Western States Water Council. Dispute resolution channels include arbitration modeled on the Interstate Compact Commission practices and possible adjudication before the Supreme Court of the United States as in Kansas v. Colorado (1998).

The Compact apportions surface water among signatory states, addressing tributaries like the Little Missouri River, Tongue River, and Bighorn River. It establishes allocation principles comparable to the Colorado River Compact (1922) and sets trigger points for reservoir releases at facilities such as Garrison Dam and Fort Peck Dam. Provisions cover consumptive uses, storage priorities, and return flow accounting, drawing on hydrologic accounting methods used by the International Joint Commission and engineering standards from the American Society of Civil Engineers. The Compact interfaces with federal projects under the Pick-Sloan Plan and recognizes rights tied to irrigation districts including the Mandan Irrigation District and municipal utilities like the City of Billings.

Implementation depends on cooperative data sharing among state agencies—state engineers of Montana, North Dakota, South Dakota, and Wyoming—and federal partners including the Bureau of Reclamation, the U.S. Army Corps of Engineers, and the U.S. Fish and Wildlife Service. Administrative tasks include streamflow measurement using methods endorsed by the United States Geological Survey and compliance monitoring analogous to regimes under the Clean Water Act and the Endangered Species Act. The Compact’s administration coordinates with regional bodies such as the Upper Great Plains Regional Water Commission and technical panels similar to those used by the Northwest Power and Conservation Council.

Litigation arising under the Compact has involved interstate claims and federal oversight, echoing cases like Colorado v. New Mexico and Wyoming v. Colorado. Disputes have implicated rights of Native American tribes such as the Crow Tribe of Montana and the Fort Belknap Indian Community where reserved water rights recognized in decisions like Winters v. United States affect allocations. Enforcement and interpretation have at times invoked the Doctrine of Prior Appropriation and have required evidentiary records consistent with the Federal Rules of Evidence when matters proceeded to the Supreme Court of the United States or to interstate arbitration panels.

The Compact’s allocation framework influences ecosystems associated with the Missouri Breaks, Turtle Mountain, and riparian corridors supporting species protected under the Endangered Species Act, including habitats for migratory birds coordinated through the U.S. Fish and Wildlife Service and wetlands recognized by the Ramsar Convention-aligned efforts. Economic effects touch agriculture in regions served by the Milk River Project, energy production near Fort Peck Dam and Garrison Dam hydropower facilities, and navigation corridors linked to the Port of Bismarck and regional rail infrastructure like the Burlington Northern Santa Fe Railway. Recreational economies connected to Yellowstone National Park, Little Bighorn Battlefield National Monument, and angling in tributaries intersect with conservation programs run by organizations such as The Nature Conservancy and the National Audubon Society.