(CN) – Montana’s attorney general on Monday called a U.S. Supreme Court special master’s ruling in a dispute with Wyoming over water rights is a “big win” for water users.

The U.S. Supreme Court earlier had appointed Special Water Master Barton Thompson to decide the case that was first filed in 2007. On Monday, Thompson found that Montana has the right to fill the Tongue River Reservoir to pre-1950 levels, under the Yellowstone River Compact that Congress approved in 1950. Prior to Thompson’s decision, Wyoming was withholding some of the flows from the Yellowstone River, which drains into the Tongue River Reservoir in southeastern Montana.

“Today’s decision is a big win for the state of Montana and its water users,” Montana Attorney General Tim Fox said in a press release. “I am pleased that the special master recognized the state of Montana’s right to assert its compact rights, and has ruled that Montana is entitled to a specific judicial declaration of its rights.”

Earlier this year, the U.S. Supreme Court issued an order acknowledging that Montana had suffered damages by Wyoming’s refusal to abide by the compact. Montana had sought monetary restitution, but Thompson declined the request, at least temporarily, “subject to Montana’s right to pursue a water remedy instead of monetary damages.”

Wyoming Gov. Matt Mead said he was pleased with the special master’s decision. The Cowboy State did win part of its argument in that Thompson agreed that an injunction Montana sought wasn’t necessary.

“The special master has issued a solution with two practical options for the damages owed to Montana,” Mead said. “We look forward to working with our neighbors to quickly bring this case to a close. I thank the special master for his work as well as the Attorney General’s and State Engineer’s offices for their exceptional work.”

Eric Sell, director of communications for the Montana Department of Justice, said they’re pleased with the decision as well, which mainly will impact agricultural irrigators. Sell added, however, that both sides have a right to file exceptions to the water master’s conclusion, so the case might not be finished.

“Both sides have a right to appeal, but I’m not sure Montana has any plans to do that at this time,” Sell said.