A federal courthouse in Washington, D.C. was packed on Friday morning as oral arguments were heard in a closely watched land-into-trust case.

What was supposed to be a 30-minute hearing ended up lasting twice as long. The outcome of the dispute will determine whether or not the Cowlitz Tribe of Washington will be joining the Indian gaming industry, and could have far-reaching effects for Native American Indians.

Construction began on the $510 million project in January, and with the casino wall’s going up on the Cowlitz Reservation outside La Center along Interstate 5, is progressing quickly. However, an ongoing lawsuit between the tribe and opponents including neighboring Oregon’s Confederated Tribes of the Grand Ronde, among others, are doing their best to halt its construction and see that it never opens in the spring of 2017 as planned.

The opponent’s case, heard by the D.C. Circuit Court of Appeals, is largely based on the February 2009 Carcieri v. Salazar ruling by the U.S. Supreme Court. The justices determined the term “now under Federal jurisdiction” only referred to tribes that were federally recognized at the time the Indian Reorganization Act became law, and land could not be taken into trust by the Bureau of Indian Affairs (BIA) for tribes that were under federal jurisdiction after 1934. While the Cowlitz tribe didn’t receive federal recognition until 2000, in December 2014 U.S. District Court Judge Barbara J. Rothstein called the statue’s wording ambiguous and sided with the tribe and the lawsuit was dismissed.

The Grand Ronde Tribes, however, are hoping to expand Carcieri in dramatic fashion. The court was told by Attorney Lawrence S. Robbins that in addition to being “under federal jurisdiction” a tribe must have been “recognized” in 1934 in order to benefit from the Indian Reorganization Act. Robbins told the court that the Cowlitz tribe was “terminated throughout the 20th century,” and that a BIA document from that time proves that in 1934 the Cowlitz were no longer a cohesive tribal community, according to indianz.com.

Two judges on the panel of three noted that in the late 1800’s the U.S. was engaged with the tribe in formal negotiations. Robbins and the justices went back and forth regarding the talks and whether they alone provided an assumption that the tribe was “recognized.” To that point, John L. Smeltzer of the Department of Justice noted that whether the tribe was “recognized” is not at issue in the lawsuit and those documents cited by Grand Ronde address the BIA’s “neglect” of the Cowlitz people. Smeltzer said they cannot be interpreted as the tribe being somehow terminated. He rejected the concept of “administrative termination” saying that the Department of the Interior cannot do that, only Congress can.

The approval of the Cowlitz Tribe’s land-into-trust application by the BIA was the first decision of its kind for a tribe which was newly recognized. The D.C. Circuit is the first appellate court to test whether the BIA’s decision can survive without Congress getting involved. The decision could be months away.