SPOKANE, Wash. (AP) – The Kalispel Tribe sued the U.S. government on Tuesday over its approval of a rival casino project by the Spokane Tribe in the lucrative Spokane gambling market.

The Kalispel Tribe sued the Department of the Interior for giving the Spokane Tribe a rare approval for an off-reservation casino about two miles (3.2 kilometers) from the Kalispel’s 15-year-old Northern Quest Casino.

The new casino “will have a devastating impact on Northern Quest, which funds nearly all of the Kalispel Tribe’s government operations,” said the lawsuit filed in federal court for the Eastern District of Washington.

Federal law requires the Interior secretary to consider the detrimental impacts of a new casino on nearby Indian tribes, the lawsuit said.

The Spokane Tribe contends the Kalispels are seeking to avoid “fair competition from us.”

Spokane Tribal Council Chair Carol Evans said the new casino, under the Hard Rock Hotel banner, was approved last year by both the Interior Department and Washington Gov. Jay Inslee, and “is located in the heart of our ancestral homeland.” The Spokane Tribe’s reservation is just northwest of Spokane, which is in eastern Washington state.

The Kalispels contend the Interior Department violated the Indian Gaming Regulatory Act and seeks to block the new casino, which is under construction on the plains just west of Spokane in the suburb of Airway Heights.

Inslee last June decided the Spokanes can proceed with the $400 million project, first proposed a decade ago, despite massive opposition from civic leaders in the region.

Leaders of the impoverished Spokane Tribe contend the casino will help lift members out of poverty by providing thousands of jobs.

Over the years, the Kalispels were able to enlist many Spokane political and business leaders as allies, in part by arguing that the Spokane Tribe casino might become a factor in future decisions on possibly closing nearby Fairchild Air Force Base.

Inslee said he wanted to respect the sovereignty and economic development wishes of the Spokane Tribe, while also generating millions of tax dollars for state and local governments.

The new project could take a decade to complete. It will include a casino, hotel, restaurants, convention facilities, bars, tribal cultural center, police and fire stations, spa and retail space.

It marks only the second time an off-reservation Indian casino has been approved in Washington. The first was Northern Quest, which has proven to be a successful business for the Kalispels, whose reservation is near the town of Usk in Pend Oreille County. Northern Quest has become a big player in the region’s tourism industry and has about 2,000 employees.