An Arizona tribe with plans to build a casino and resort on property it purchased near Glendale scored a key victory Tuesday when a federal appeals court ruled that the U.S. Department of Interior rightfully awarded reservation status to a section of the land.

The 9th Circuit U.S. Court of Appeals issued a split decision rejecting arguments by the city of Glendale that the property is ineligible for such status because it falls within its corporate limits. The property is an unincorporated island of Maricopa County and bordered on three sides by Glendale.

Tohono O’odham Nation Chairman Ned Norris Jr. characterized the lawsuit that challenged the U.S. Department of the Interior’s decision to award reservation status in 2010 as another delaying tactic.

“Just as courts and federal agencies have done eight straight times before, the 9th Circuit weighed the arguments and then ruled in the nation’s favor,” he said in a statement. “The court reaffirmed today that when the federal government makes a commitment to Native peoples, it will stand by those commitments.”

At issue was whether federal law permitted the tribe to convert the property it quietly purchased in 2003 into an Indian reservation, which would strip authority from state and local officials who argued the casino project clashes with zoning and state laws.

Federal law generally bars gambling on reservations created after 1988, but there are a few exceptions.

The tribe purchased the property with congressionally allocated money it was given after a federal government dam caused extensive flooding of its original reservation.

Glendale, the state of Arizona and another tribe had sued to overturn the DOI decision. A spokeswoman for the city and for the state Attorney General’s Office did not immediately respond to requests for comment Tuesday.

About 30,000 people live within two miles of where the casino is to be erected.

The tribe still faces other legal and regulatory challenges in building a casino. Opponents, including other tribes, contend the Tohono O’odham Nation went “reservation shopping” with the government’s money and shouldn’t be allowed to turn just any piece of property it purchases into a reservation and then a casino the size of the Venetian Hotel and Casino in Las Vegas.