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Montana makes call under compact

by Wyoming Livestock Roundup

Buffalo – During an April 21 meeting of the Powder and Tongue River Basin Advisory Group, Wyoming Senior Assistant Attorney General Chris Brown revealed that Montana made a call on April 10 to fill Tongue River Reservoir. 

“We have been working on addressing the call,” Brown said during the meeting. “They demanded we shut off unauthorized uses, free river uses and post-1950 water rights in Wyoming on the Tongue River.”

Brown also noted that Montana stipulated that pre-1950 water rights be taken in accordance with their rights. 

“Since they made their call, the Water Commissioners have been looking very hard at what we have going on today,” he explained. “At this point, we have had no post-1950 rights on because it is too early in the season.”

Measurements have been taken on all reservoirs that have post-1950 water rights. 

“Anything stored after the call date under a post-1950 right will have to be released if Tongue River Reservoir doesn’t fill,” Brown continued, noting that the determination will not be made until after the end of runoff, which is usually in the middle of June. 

Montana’s actions

Montana has already reduced flows out of the reservoir to 95 cubic feet per second (CFS). 

“Basically, spring has been dry. Montana is at least fearful that its reservoir won’t fill. They know they can’t get the post-50s stored water unless they make the call,” Brown said. “We responded and said there are no direct uses, but we said we would continue to monitor the situation.”

Brown also explained that Montana’s system for regulation is very different from Wyoming’s, and there are no commissioners to regulate water unless water users request one be appointed. 

“We have asked that they appoint water commissioners to make sure water is going to their pre-50s rights and not their post-50s,” he said. “We need to have these commissioners in place to make sure the water is shepherded to where it has to go.”

Previous water action

Brown’s announcement comes as the Montana versus Wyoming and North Dakota case awaits a response on exceptions that were filed. The case is deeply rooted in water rights in the Tongue River Basin, and Brown detailed the case during the meeting.

“In 2007, Montana filed suit in the U.S. Supreme Court,” said Brown. “They alleged violations of the Yellowstone River Compact in the Tongue River Basin.”


The case went to trial from October to December 2013 in Billings, Mont., and closing arguments were held in California in May 2014. 

For Wyoming to be liable, court-appointed Special Master Barton Thompson concluded that Montana must make a call, which occurred in 1981, 2004 and 2006. In 1981, Tongue River Reservoir filled anyway, meaning no liability was present.

After determining there were shortages in 2004 and 2006, the next determination was as to how much. 

“Wyoming’s argument was beneficial use at the time of the compact,” Brown explained. “Beneficial use is depletion for the activities of man. It cannot include fish or things that are non-consumptive.”

Evidence showed that Tongue River Reservoir had a contract for 32,000 acre-feet, said Wyoming. Montana asserted that they had a right to 127,324 acre-feet of water, which was figured through a complicated process. 

“Their latest assertion is there is no limit to the amount of water they have a right to, which is concerning because we have to know when the reservoir is full before we call off our post-50s water rights,” Brown said. 

Recent developments

After 25 days of trial, Thompson came to the conclusion that Wyoming wasn’t liable for damages in 13 of 15 years – a decision he issued in his Second Interim Report

“We were liable in 2004 and 2006 in the amount of 1,356 acre-feet total,” Brown said. “That is what the case came down to.”

However, in the decision, Brown noted that Thompson largely avoided the issue as to what amount of water Montana has a right to, saying “at least 32,000 acre-feet plus carryover is their right.”

Thompson laid out his recommendations to the Supreme Court in his Second Interim Report, which was released December 2014, at which point the Supreme Court made a decision.

“The Supreme Court sent down an order on Feb. 23,” Brown continued. “Basically, the Supreme Court said there isn’t a whole lot of water at stake.”

Brown said. “Exceptions were due April 9, and replies to the exceptions are due May 8.”


Both Montana and Wyoming filed one exemption. 

Wyoming’s exception noted that the liability was clear, and the state said it is willing to pay for those damages. 

“The evidence was there that water was available for the state or its users to purchase out of the Tongue River Reservoir from the Northern Cheyenne tribe,” Brown explained. “They could have covered their shortfalls.”

The Compact also notes that if one state can replace what they are contracted to receive, they should. The Northern Cheyenne tribe was selling water at between seven and 15 dollars per acre-foot during the years of shortage, and Wyoming noted, in their exception, that the state will pay the maximum amount of $20,340, plus interest using Wyoming’s rate of seven percent. 

“We said, ‘The Supreme Court is right. This case isn’t big enough to keep going, so we will give Montana a check,’” Brown noted. 

However, he added that Montana doesn’t like the idea. 

“Montana has contended that they have never been after damages,” Brown continued. “They want to know what the actual water right of Tongue River Reservoir is.”

Specifically, Montana asked that the Supreme Court remand the decision back to Thompson for his determination on exactly what the extent of the water rights are for the reservoir. 

“This case already has a long, tortured history,” Brown said, “but anyone who knows water law knows that they are usually long, long cases.

Yellowstone Compact

The Yellowstone River Compact went into effect on Jan. 1, 1970.

“Our interpretation of the Compact is that is doesn’t protect those pre-1950 rights, it just recognized them,” Wyoming Senior Assistant Attorney General Chris Brown said. 

“Montana complained that they believed the Compact froze the amount of water Wyoming could use to that amount Wyoming used in 1950,” he continued. “They said we couldn’t have new storage facilities, new direct flow diversions or pumping associated with coalbed methane because we can’t increase our consumption.”

However, Wyoming felt that the motivation was the idea of increased efficiencies, which meant reduced flows were returned to Montana. 

The Supreme Court allowed Montana to file suit and then appointed Special Master Barton Thompson, Jr. to hear the case and provide recommendations.


Saige Albert is managing editor of the Wyoming Livestock Roundup and can be reached at

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