State officials sought a temporary ban on play, which U.S. District Judge Lynn Winmill denied Monday.
The gambling compact between the state and tribe says both sides have 60 days to call for arbitration to settle disputes before they can sue each other, Winmill ruled. Because Idaho filed a lawsuit during the 60-day window, it violated the agreement, the judge said.
"For now, the court will stay the lawsuit because the parties are within the 60-day period in which the compact unambiguously prohibits the state from filing this lawsuit," Winmill wrote in his decision.
Idaho and the tribe have until July 7 to file a report to the court on the status of a solution.
State officials expressed disappointment in the ruling, given the "plain language" of the compact.
"But the State of Idaho remains committed to enforcing the rule of law that limits gambling in tribal casinos to clearly approved games and poker isn't one of them," Gov. C.L. "Butch" Otter said in a prepared statement.
Tribal attorney Eric Van Orden said the tribe believes it has the legal right to offer poker.
"The court agreed with our interpretation of the gaming compact and reinforced what we've been saying all along, that the state jumped the gun and violated the provisions of our agreement when it raced to the courthouse with this unnecessary lawsuit," Van Orden said.
The casino has been a major success for the tribe and has grown considerably since it opened nearly two decades ago. It offers slot machines, bingo and off-track betting. The poker room opened May 2.