(CNN) It was peacetime when the USS Conestoga departed from California's Golden Gate strait on March 25, 1921, but in one of the biggest maritime mysteries the vessel disappeared without a trace.

The Navy seagoing tugboat and its 56 officers and crew went missing so long ago that the famous bridge that spans the Golden Gate did not yet exist.

On Wednesday -- nearly 95 years after the Navy declared the Conestoga and its crew lost -- the shipwreck's discovery was officially announced by the National Oceanic and Atmospheric Administration and the Navy.

The wreck was first discovered in 2009 in the Greater Farallones National Marine Sanctuary about 20 miles west of San Francisco, and an investigation initiated in 2014 confirmed that the wreckage was the missing Navy vessel.

Wreckage photos matched w/ Naval History & Heritage Command's collection confirmed Conestoga #historymystery pic.twitter.com/k9r48BfwO8 — U.S. Naval History (@NavyHistoryNews) March 23, 2016

"After nearly a century of ambiguity and a profound sense of loss, the Conestoga's disappearance no longer is a mystery," NOAA Deputy Administrator Manson Brown said in a news release.

Read More