In December 2014, President Obama signed the National Defense Authorization Act (NDAA), passed by Congress to provide the budget and appropriations to sustain the Department of Defense. Tucked into the bill at the last minute – and without public debate – was a provision to hand thousands of acres of protected land in Arizona to an international mining company.

The deal nationalized 5,300 acres of land belonging to Resolution Copper Mining, an Australian-British jointly owned corporation, in exchange for privatizing 2,400 acres of national forest to be mined by Resolution for copper ore.

The land is considered sacred by the local San Carlos Apache tribe, which uses it for rituals. Some of the terrain at Oak Flat – the disputed land which was taken from the tribe’s reservation through executive order in 1902 – will be destroyed through the company’s use of “block-cave” mining. Through underground detonations, the mined land will collapse, creating a crater-like 1,000 foot pit where the copper ore will be harvested.

Congressmen from Arizona tried to complete the deal for years, but with little success. In 2005, then-Rep. Rick Renzi was the first delegate from the state to propose the deal (he was later sent to prison for corruption charges, including extortion related to the land swap). The deal eventually passed in the House in 2011, but made it no further, and it died in the House twice in 2013. On its own, the bill lacked support.

In 2014, however, the state’s delegates saw their chance. Representatives Paul Gosar and Ann Kirkpatrick successfully pushed for its inclusion as a rider in the “must-pass” NDAA. Rep. Tom Cole (R-Okla.), co-chairman of the Native American Caucus, tried to strip the amendment in the House Rules Committee, but he was outvoted by fellow Republicans. The bill cleared the House by an overwhelming majority.

Tom Coburn (R-Okla) tried to have the provision removed in his chamber as well, but he also failed. The bill received support from both of Arizona’s senators – Jeff Flake, who was once a lobbyist for Rio Tinto, Resolution’s parent company, and John McCain, a recipient of contributions from Rio Tinto affiliates. Two months before the bill's passage, McCain wrote an op-ed promising nearly 4,000 jobs to the blighted area if the deal were approved.

The deal – referred to as “Southeast Arizona Land Exchange and Conservation” in Section 3003 of the NDAA, appears on page 1,103 in the 1,648-page law.

This is not the first dispute between the Apaches and the federal government. A series of armed conflicts known as the Apache Wars lasted from 1849 to 1906. In the midst of this conflict, President Grant created the San Carlos Reservation in 1872, which served as a kind of concentration camp for various tribes at odds with the U.S.’s westward expansion.

The reservation shrank over the decades. In 1902, President Roosevelt re-drew the reservation’s boundaries to free up mineral lands for excavation. In 1929, the government constructed the Coolidge Dam and San Carlos Reservoir over the objections of the Apaches, who claimed the project was a treaty violation and a desecration of ancestral graves.

But at times, the government has worked to conserve the Apache’s sacred land. In 1905, the newly created Tonto National Forest included the now-disputed Oak Flat territory. In 1955, President Eisenhower banned mining at the Oak Flat campground, and President Nixon’s Department of Interior renewed the ban in 1971.

When the NDAA was signed in 2014, President Obama’s secretary of the Interior expressed “profound disappointment with the lack of regard for lands considered sacred by Indian tribes.”

While the Oak Flat territory is no longer part of the San Carlos Reservation, the Apaches are fighting to protect the land and to repeal the transfer deal before Resolution acquires the site.

In February 2015, hundreds of Apaches marched 44 miles from the reservation to Oak Flat, with many pledging to occupy the holy land until the exchange is called off. The site is also a burial ground. The great-great grandmother of Terry Rambler, the current chairman of the tribe, is buried at Oak Flat.

According to Rep. Alan Grayson (D-Fla.), the land contains approximately $130 billion worth of copper ore. Resolution anticipates the project will generate $60 billion in economic benefits and 1,400 direct jobs, but the Apaches are skeptical they will prosper from the mining operation. The block-cave technique is less labor intensive than the cut-and-fill technique used at nearby mines, and Congress blocked an amendment that would have required Resolution to station its remote operations center close by.

Also, the Apaches will see little of the estimated $20 billion in federal and state tax revenue. In Arizona, tax revenue from mining is distributed to municipalities according to population. The state capital, Phoenix, located an hour west of the proposed mining site, has a population 100 times greater than that of the San Carlos Reservation.

After three months of occupation and peaceful protesting, the San Carlos Apache tribal council passed a symbolic resolution repealing the deal, and leaders pledged to take the issue back to Congress. Earlier this month, former tribe chairman Wendsler Nosie declared:

[W]e are announcing the next step in our battle for repeal, and that’s a march on Washington…Alliances with other tribes, universities, religious groups and outraged citizens continue to grow in groundswell proportion—our support numbers have just gone crazy. The month of June will be a month of protest in the streets and in congressional offices.

On June 17, Rep. Grijalva (D-Ariz.) introduced legislation to block the deal by repealing Section 3003 of the NDAA. The bill, called the "Save Oak Flat Act," cites the cultural disruption and environmental effects of the mining plan. It also notes – directly rebuking the process by which the land exchange was passed – that federal law requires "meaningful consultations with affected Indian tribes" before policies are enacted that impact them.

The bill is cosponsored by 3 Republicans and 11 Democrats.

Resolution Project Director Andrew Taplin has pledged not to mine near the most holy Apache sites, including Apache Leap and the Oak Flat campground. Taplin also claims that the Apache leadership has not responded to requests for dialogue and negotiation but is optimistic that a compromise can be reached that satisfies both parties.