October Term 2010 · Docket 137 ORIG.
Does a 1945 compact freeze water consumption or only diversion amounts?
Montana and Wyoming dispute whether a 1945 compact limits total water use or only the volume diverted from the river.
Verified source milestones
- — An official oral-argument transcript was verified.
The arguments, in order
This case may have been argued more than once. Each entry below uses that session's official transcript. Later arguments do not erase earlier ones.
Argument 1 ·
What happened at the argument
General Bullock argued that the compact freezes total water consumption.
Justice Roberts noted that beneficial use is irrigation and questioned if usage increased after diversion.
Justice Sotomayor asked if pre-1950 irrigators could change their crops.
Justice Kennedy suggested the compact language might only show reduced water amounts.
Read the official transcript for this argument · Official argument details
Sources used for this argument breakdown
- Official Supreme Court Transcript — file page 10, lines 17-41 — Transcript, file page 10, lines 17-41
- Official Supreme Court Transcript — file page 25, lines 35-21 — Transcript, file page 25, lines 35-21
- Official Supreme Court Transcript — file page 3, lines 19-3 — Transcript, file page 3, lines 19-3
- Official Supreme Court Transcript — file page 3, lines 7-17 — Transcript, file page 3, lines 7-17
- Official Supreme Court Transcript — file page 4, lines 29-37 — Transcript, file page 4, lines 29-37
- Official Supreme Court Transcript — file page 4, lines 5-13 — Transcript, file page 4, lines 5-13
- Official Supreme Court Transcript — file page 42, lines 35-35 — Transcript, file page 42, lines 35-35
- Official Supreme Court Transcript — file page 5, lines 13-19 — Transcript, file page 5, lines 13-19
- Official Supreme Court Transcript — file page 5, lines 35-51 — Transcript, file page 5, lines 35-51
- Official Supreme Court Transcript — file page 6, lines 51-3 — Transcript, file page 6, lines 51-3
- Official Supreme Court Transcript — file page 6, lines 9-23 — Transcript, file page 6, lines 9-23
- Official Supreme Court Transcript — file page 7, lines 11-33 — Transcript, file page 7, lines 11-33
- Official Supreme Court Transcript — file page 8, lines 13-13 — Transcript, file page 8, lines 13-13
- Official Supreme Court Transcript — file page 8, lines 15-31 — Transcript, file page 8, lines 15-31
- Official Supreme Court Transcript — file page 8, lines 51-19 — Transcript, file page 8, lines 51-19
- Official Supreme Court Transcript — file page 9, lines 37-47 — Transcript, file page 9, lines 37-47
A citizen's guide to the whole case
What this case is about
Montana and Wyoming argue over the meaning of a 1945 interstate compact. The states disagree on whether the agreement freezes total water consumption or only the amount diverted from the river. This distinction determines how much water each state may use for irrigation.
Official sources for this section
- Official Supreme Court Transcript — file page 25, lines 35-21 — Transcript, file page 25, lines 35-21
- Official Supreme Court Transcript — file page 3, lines 19-3 — Transcript, file page 3, lines 19-3
- Official Supreme Court Transcript — file page 42, lines 35-35 — Transcript, file page 42, lines 35-35
How the case got here
The Supreme Court heard oral argument in this case on January 10, 2011.
Official sources for this section
- Official Supreme Court Transcript — file page 3, lines 7-17 — Transcript, file page 3, lines 7-17
What each side wants
Montana wants the Court to interpret the compact as freezing total water consumption.
Wyoming wants the Court to interpret the compact as freezing only the amount of water diverted.
Official sources for this section
- Official Supreme Court Transcript — file page 25, lines 35-21 — Transcript, file page 25, lines 35-21
- Official Supreme Court Transcript — file page 3, lines 19-3 — Transcript, file page 3, lines 19-3
- Official Supreme Court Transcript — file page 42, lines 35-35 — Transcript, file page 42, lines 35-35
What each side says
Montana argues that the compact limits the total volume of water a state can use.
Wyoming argues that the compact limits only the physical amount of water taken from the river.
Official sources for this section
- Official Supreme Court Transcript — file page 25, lines 35-21 — Transcript, file page 25, lines 35-21
- Official Supreme Court Transcript — file page 3, lines 19-3 — Transcript, file page 3, lines 19-3
- Official Supreme Court Transcript — file page 42, lines 35-35 — Transcript, file page 42, lines 35-35
What the justices asked
Justice Ginsburg asked for the specific language that freezes consumption rather than diversion.
Justice Kennedy asked why Article V(A) does not simply restate the beneficial use issue.
Official sources for this section
- Official Supreme Court Transcript — file page 10, lines 17-41 — Transcript, file page 10, lines 17-41
- Official Supreme Court Transcript — file page 4, lines 29-37 — Transcript, file page 4, lines 29-37
- Official Supreme Court Transcript — file page 4, lines 5-13 — Transcript, file page 4, lines 5-13
- Official Supreme Court Transcript — file page 5, lines 13-19 — Transcript, file page 5, lines 13-19
- Official Supreme Court Transcript — file page 5, lines 35-51 — Transcript, file page 5, lines 35-51
- Official Supreme Court Transcript — file page 6, lines 51-3 — Transcript, file page 6, lines 51-3
- Official Supreme Court Transcript — file page 6, lines 9-23 — Transcript, file page 6, lines 9-23
- Official Supreme Court Transcript — file page 7, lines 11-33 — Transcript, file page 7, lines 11-33
- Official Supreme Court Transcript — file page 8, lines 13-13 — Transcript, file page 8, lines 13-13
- Official Supreme Court Transcript — file page 8, lines 15-31 — Transcript, file page 8, lines 15-31
- Official Supreme Court Transcript — file page 8, lines 51-19 — Transcript, file page 8, lines 51-19
- Official Supreme Court Transcript — file page 9, lines 37-47 — Transcript, file page 9, lines 37-47
Why it matters
The interpretation determines the total volume of water available for agricultural irrigation in the basin. It defines the legal boundary between diversion limits and consumption caps for upstream and downstream states.
Official sources for this section
- Official Supreme Court Transcript — file page 25, lines 35-21 — Transcript, file page 25, lines 35-21
- Official Supreme Court Transcript — file page 3, lines 19-3 — Transcript, file page 3, lines 19-3
- Official Supreme Court Transcript — file page 42, lines 35-35 — Transcript, file page 42, lines 35-35
What happens next
This article currently covers the argument record. Use the official docket link for later case activity.
Official sources for this section
- Official Supreme Court Transcript — file page 10, lines 17-41 — Transcript, file page 10, lines 17-41
- Official Supreme Court Transcript — file page 3, lines 7-17 — Transcript, file page 3, lines 7-17
- Official Supreme Court Transcript — file page 4, lines 29-37 — Transcript, file page 4, lines 29-37
- Official Supreme Court Transcript — file page 4, lines 5-13 — Transcript, file page 4, lines 5-13
- Official Supreme Court Transcript — file page 5, lines 13-19 — Transcript, file page 5, lines 13-19
- Official Supreme Court Transcript — file page 5, lines 35-51 — Transcript, file page 5, lines 35-51
- Official Supreme Court Transcript — file page 6, lines 51-3 — Transcript, file page 6, lines 51-3
- Official Supreme Court Transcript — file page 6, lines 9-23 — Transcript, file page 6, lines 9-23
- Official Supreme Court Transcript — file page 7, lines 11-33 — Transcript, file page 7, lines 11-33
- Official Supreme Court Transcript — file page 8, lines 13-13 — Transcript, file page 8, lines 13-13
- Official Supreme Court Transcript — file page 8, lines 15-31 — Transcript, file page 8, lines 15-31
- Official Supreme Court Transcript — file page 8, lines 51-19 — Transcript, file page 8, lines 51-19
- Official Supreme Court Transcript — file page 9, lines 37-47 — Transcript, file page 9, lines 37-47
Official Court provenance
Official docket and case history · Official Supreme Court oral-argument detail page
Title and summary sources
- Official Supreme Court Transcript — file page 25, lines 35-21 — Transcript, file page 25, lines 35-21
- Official Supreme Court Transcript — file page 3, lines 19-3 — Transcript, file page 3, lines 19-3
- Official Supreme Court Transcript — file page 42, lines 35-35 — Transcript, file page 42, lines 35-35
- Official Supreme Court Transcript — file page 25, lines 35-21 — Transcript, file page 25, lines 35-21
- Official Supreme Court Transcript — file page 3, lines 19-3 — Transcript, file page 3, lines 19-3
- Official Supreme Court Transcript — file page 42, lines 35-35 — Transcript, file page 42, lines 35-35
Revision history
- Revision 1 · Official Transcript ·
Correction: Rewritten to the concise citizen-facing editorial standard.
- Revision 2 · Official Transcript ·
Correction: Migrated to the dated official Court activity contract without model use.