Housed in a converted infantry barracks on a former U.S. Army base, San Francisco's Presidio Social Club is serving foie gras, even though California imposed a ban on July 1.
Animal rights activists fought for the law because foie gras is made by farmers who reportedly force-feed ducks or geese to fatten their livers.
The Presidio Social Club's owner, Ray Tang claims the restaurant can legally ignore Califoria state law because the Presidio, now managed as a national park, has remained federal property, after being decommissioned by the Army.
Businesses on federal property must adhere to federal regulations, which trump state ones, Tang told Reuters.
On Saturday, diners filled all the restaurant's 117 seats. A dozen activists, from the Animal Protection and Rescue League, chanted outside.
Dana Portnoy, of the Animal Protection and Rescue League, told Reuters of the horrific conditions in a foie gras facility: ducks too sick to stand up, asphyxiating on their own blood from feeding tube wounds, or choking on the corn they were forced to swallow.
However, Tang claims that his restaurant is getting its foie gras from a humane source in New York's Hudson Valley: "Birds of that type naturally gorge themselves. I do not believe they suffer."
The Animal Protection and Rescue League has asked the federal agency managing the park, the Presidio Trust, to enforce the state ban, but the trust has yet to state its legal position.