ABOUT an hour east of Phoenix, near a mining town called Superior, men, women and children of the San Carlos Apache tribe have been camped out at a place called Oak Flat for more than three months, protesting the latest assault on their culture.

Three hundred people, mostly Apache, marched 44 miles from tribal headquarters to begin this occupation on Feb. 9. The campground lies at the core of an ancient Apache holy place, where coming-of-age ceremonies, especially for girls, have been performed for many generations, along with traditional acorn gathering. It belongs to the public, under the multiple-use mandate of the Forest Service, and has had special protections since 1955, when President Dwight D. Eisenhower decreed the area closed to mining — which, like cattle grazing, is otherwise common in national forests — because of its cultural and natural value. President Richard M. Nixon’s Interior Department in 1971 renewed this ban.

Despite these protections, in December 2014, Congress promised to hand the title for Oak Flat over to a private, Australian-British mining concern. A fine-print rider trading away the Indian holy land was added at the last minute to the must-pass military spending bill, the National Defense Authorization Act. By doing this, Congress has handed over a sacred Native American site to a foreign-owned company for what may be the first time in our nation’s history.

The Apache are occupying Oak Flat to protest this action — to them, a sacrilegious and craven sell-off of a place “where Apaches go to pray,” in the words of the San Carlos Apache tribal chairman, Terry Rambler. The site will doubtless be destroyed for any purpose other than mining; Resolution Copper Mining will hollow out a vast chamber that, when it caves in, will leave a two-mile-wide, 1,000-foot-deep pit. The company itself has likened the result of its planned mining at Oak Flat to that of a nearby meteor crater.

The land grab was sneakily anti-democratic even by congressional standards. For more than a decade, the parcel containing Oak Flat has been coveted by Rio Tinto, Resolution’s parent company — which already mines on its own private land in the surrounding area — for the high-value ores beneath it.

The swap — which will trade 5,300 acres of private parcels owned by the company to the Forest Service and give 2,400 acres including Oak Flat to Resolution so that it can mine the land without oversight — had been attempted multiple times by Arizona members of Congress on behalf of the company. (Among those involved was Rick Renzi, a former Republican representative who was sent to federal prison in February for three years for corruption related to earlier versions of the land-transfer deal.) It always failed in Congress because of lack of support. But this time was different. This time, the giveaway language was slipped onto the defense bill by Senators John McCain and Jeff Flake of Arizona at the 11th hour. The tactic was successful only because, like most last-minute riders, it bypassed public scrutiny.

If Oak Flat were a Christian holy site, or for that matter Jewish or Muslim, no senator who wished to remain in office would dare to sneak a backdoor deal for its destruction into a spending bill — no matter what mining-company profits or jobs might result. But this is Indian religion. Clearly the Arizona congressional delegation isn’t afraid of a couple of million conquered natives.

The truth is that for Mr. McCain, Mr. Flake and others who would allow this precious public land to be destroyed, it’s not only the Indians who are invisible. The rest of us are also ghosts, remnants of a quaint idea of democracy.

Oak Flat may still be saved, albeit with difficulty, since the bill’s language stipulates quite simply that 60 days after the federal “environmental impact statement” is complete, the land will belong to Resolution — in other words, that the swap will occur no matter what the environmental study says. But, like all laws and pieces of laws, it can be reversed by new legislative language.

The deal is an impressive new low in congressional corruption, unworthy of our country’s ideals no matter what side of the aisle you’re on. It’s exactly the kind of cynical maneuvering that has taught the electorate to disrespect politicians — a disdain for government that hurts everyone. If ever there was a time for Congress to prove its moral mettle to the public, this is that time. The rider should be repealed.