ANACORTES, Wash. -

Billionaire and Microsoft co-founder Paul Allen has sold a 292-acre island in the San Juans in northwest Washington state for $8 million.

The Seattle Times reports the property sold on Dec. 20.

Allan Island, named after a Navy hero, is southwest of Anacortes. Data from the Northwest Multiple Listing Service shows it was listed in 2005 for $25 million and slashed to $13.5 million in 2009.

The Windermere real-estate agent who listed the property, Wallace Gudgell, didn't immediately return the newspaper's requests for comment.

Allen bought the island in 1992 to build a vacation home. It's only accessible by private plane, boat or float plane.