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 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: 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.