Question: What country are both the San Francisco Naval Shipyard and San Francisco Bay Naval Shipyard located in?
Context: Philly Shipyard, formerly Aker Philadelphia Shipyard, is a commercial shipyard located in Philadelphia, Pennsylvania, United States on part of the site of the Philadelphia Naval Shipyard.  The commercial yard began after the United States Navy had ended most of its operations at the site. John Wills Greenslade (Bellevue, Ohio, January 11, 1880 – January 6, 1950) was a Vice Admiral in the United States Navy.  Admiral Greenslade enjoyed a significant military career during World War II.  From 1941-1944 Greenslade was Commandant, Twelfth Naval District, with additional duty as Commandant, Pacific Southern Naval Coastal Frontier.  On January 8, 1942, while he was serving at Mare Island Naval Shipyard, Greenslade urged that American-born and alien Japanese be excluded from areas of strategic importance.  On April 17, 1942, the Navy seized Treasure Island, San Francisco, California from the City of San Francisco under the direction of Vice Admiral Greenslade, and paid no compensation for the confiscated island.  Admiral Greenslade claimed Treasure Island was required for "national security" and appropriated the island for the Navy. USS "Mahan" (DDG-42), was a "Farragut"-class guided missile destroyer in the United States Navy.  She was named for Rear Admiral Alfred Thayer Mahan USN (1840–1914).  The ship was Laid down as DLG-11 by the San Francisco Naval Shipyard on 31 July 1957 and launched on 7 October 1959.  "Mahan" was sponsored by Mrs. H. P. Smith, wife of Vice Adm. Harold Page Smith, and commissioned on 25 December 1960.  "Mahan" was reclassified as a guided missile destroyer on 30 June 1975 and designated DDG-42.  USS "Mahan" was decommissioned on 15 June 1993 and stricken from the Naval Vessel Register on the same day. The San Francisco Bay Naval Shipyard was a short-lived shipyard formed in 1965 as the combination of the San Francisco Naval Shipyard (aka Hunters Point) and the Mare Island Naval Shipyard.  The combined yards were the largest naval shipyard in the world, but the desired cost savings did not materialize, and the two yards reverted to separate existences in February 1970.  The shipyard was used for radioactive testing when the United States was testing the atomic bomb.  The site has since been contaminated.  Now the Hunters Point Naval Shipyard is a Superfund site, as designated by the Environmental Protection Agency (EPA).  It is the Navy's job to clean up the site to "reasonable" levels to those who live adjacent to the shipyard. The Niles Canyon Railway (NCRy) is a heritage railway running through Niles Canyon, between Sunol and the Niles district of Fremont in the East Bay of the San Francisco Bay Area, in California, United States.  The railway is listed on the National Register of Historic Places as the Niles Canyon Transcontinental Railroad Historic District.  The railroad is operated and maintained by the Pacific Locomotive Association which preserves, restores and operates historic railroad equipment.  The NCRy features public excursions with both steam and diesel locomotives along a well-preserved portion of the First Transcontinental Railroad.  The Golden Gate Railroad Museum moved its collection from San Francisco to the NCRy in 2007 for storage and limited operations after their home at Hunters Point Naval Shipyard was shut down for redevelopment. The San Francisco Naval Shipyard was a United States Navy shipyard in San Francisco, located on 638 acre of waterfront at Hunters Point in the southeast corner of the city. The Mare Island Naval Shipyard (MINSY) was the first United States Navy base established on the Pacific Ocean.  It is located 25 miles northeast of San Francisco in Vallejo, California.  The Napa River goes through the Mare Island Strait and separates the peninsula shipyard (Mare Island, California) from the main portion of the city of Vallejo.  MINSY made a name for itself as the premier US West Coast submarine port as well as serving as the controlling force in San Francisco Bay Area shipbuilding efforts during World War II.  The base closed in 1996 and has gone through several redevelopment phases.  It was registered as a California Historical Landmark in 1960, and parts of it were declared a National Historic Landmark District in 1975. The Portsmouth Naval Shipyard Museum and the associated Lightship Museum are located on the downtown Portsmouth, Virginia, United States waterfront.  The museum covers the 250+ year relationship with the shipyard - America's oldest and largest naval shipyard located on the Portsmouth Waterfront.  The city and the shipyard have been intertwined since the founding of the Gosport Shipyard in 1767, which was later renamed Norfolk Navy Yard and finally Norfolk Naval Shipyard.  This rich history is told through exhibits, hands-on programs and special events. The Portsmouth Naval Shipyard (PNS), often called the Portsmouth Navy Yard, is a United States Navy shipyard located in Kittery on the southern boundary of Maine near the city of Portsmouth, New Hampshire.  PNS is tasked with the overhaul, repair, and modernization of US Navy submarines.  The facility is sometimes confused with the Norfolk Naval Shipyard in Portsmouth, Virginia. The United States Navy Yard, also known as the Brooklyn Navy Yard and the New York Naval Shipyard (NYNS), was a shipyard located in Brooklyn, New York, east of the Battery on the East River in Wallabout Basin, a semicircular bend of the river across from Corlears Hook in Manhattan.  It was bounded by Navy Street and Flushing and Kent Avenues, and at the height of its production of warships for the United States Navy, it covered over 200 acre .  The tremendous efforts of its 70,000 workers during World War II earned the yard the nickname "The Can-Do Shipyard."
Answer: United States