WASHINGTON – In 1974, far out in the Pacific, a U.S. ship pretending to be a deep-sea mining vessel fished a sunken Soviet nuclear-armed submarine out of the ocean depths, took what it could of the wreck and made off to Hawaii with its purloined prize.

Now, Washington is owning up to Project Azorian, a brazen mission from the days of high-stakes — and high-seas — Cold War rivalry.

After more than 30 years of refusing to confirm the barest facts of what the world already knew, the CIA has released an internal account of Project Azorian, though with juicy details taken out. The account surfaced Friday at the hands of private researchers from the National Security Archive who used the Freedom of Information Act to achieve the declassification.

The document is a 50-page article quietly published in the fall 1985 edition of Studies in Intelligence, the CIA's in-house journal that outsiders rarely get to see.

In it, the CIA describes in chronological detail a mission of staggering expense and improbable engineering feats that culminated in August 1974 when the Hughes Glomar Explorer retrieved a portion of the submarine, K-129. The eccentric industrialist Howard Hughes lent his name to the project to give the ship cover as a commercial research vessel.

The Americans buried six lost Soviet mariners at sea, after retrieving their bodies in the salvage, and sailed off with a hard-won booty that turned out to be of questionable value.

Despite the declassified article, the greatest mysteries of Project Azorian remain buried three miles down and in CIA files: exactly what parts of the sub were retrieved, what intelligence was derived from them and whether the mission was a waste of time and money. Despite the veil over the project, its existence has been known for decades.

"It's a pretty meaty description of the operation from inception to death," said Matthew Aid, the researcher who had been seeking the article since 2007, when he learned of its publication thanks to a footnote he spotted in other documents. "But what's missing in the end is, what did we get for it? The answer is, we still don't know."

Much of the operation on the scene unfolded as Soviet vessels watched and sometimes buzzed the Glomar Explorer with helicopters. The Americans told the Soviets they were conducting deep-sea mining experiments.

Journalists broke the story in 1975, led by Seymour Hersh, then of The New York Times, and columnist Jack Anderson. The CIA maintained its silence except for declassifying a videotape of the burial of the Soviet seamen that was turned over to Russian President Boris Yeltsin in the early 1990s.

Now the CIA article, written by an unidentified participant in the operation, brings back to life a time of brinkmanship between two nuclear-armed superpowers as they raced to uncover each other's military secrets. That competition ranged from space, across continents, to the ocean depths.

For Washington, that meant sparing no expense to retrieve a mammoth vessel loaded with nuclear arms, codes and Soviet technology.

Yet the disclosed sections of the article hint that not much of value was found, just as long-ago reporting on the episode concluded.

It only claims "intangibly beneficial" results such as a boost in morale among intelligence officers and advances in heavy-lift technology at sea. The author argues the value in mounting the operation was in proving it could be done — an assertion that does not point to a trove of intelligence.

"Lifting a submarine weighing approximately 1,750 tons from a depth of 16,500 feet had never been attempted or accomplished anywhere before," the article says. "A government or organization too timid to undertake calculable risks in pursuit of a proper objective would not be true to itself or to the people it serves."

To researchers, that sounds like bureaucratic justification for a project thought to have cost over $1.5 billion in today's dollars.

Accounts vary about what was actually brought back. Years later, Russian officials concluded the CIA recovered at least two nuclear-armed torpedoes, not much of a bounty. In other tellings, most of the vessel broke up and fell back to the ocean floor, yielding little. The article does not settle such questions.

Nor does it say why the submarine is thought to have gone down.

The saga began in March 1968 when K-129, carrying three ballistic missiles armed with nuclear warheads as well as its torpedoes, sank 1,560 miles northwest of Hawaii with all hands lost. It took six years to ready the Glomar Explorer, create a winching system and sail to the wreck.

The CIA article carefully recounts the engineering hurdles of the operation, discloses the fears of the U.S. crew that Soviets would try to land on the Glomar Explorer and confirms that plutonium contamination was found in the salvage, apparently leaking from retrieved torpedoes.

But much else on the salvage is redacted and the CIA's story ends with the ship going to Hawaii, leaving out what was taken and its significance once investigated back on land.