Sponsored by the Vaca Valley Volks, the Benicia Bridge walk started at the Benicia Senior Center on beautiful day for a walk. The walk went along Benicia streets and through the gates to the former Benicia Arsenal. The Benicia Arsenal was a large military reservation located next to Suisun Bay in Benicia, California. For over 100 years, the arsenal was the primary US Army Ordnance facility for the West Coast of the United States. The headquarters building and other buildings supporting the Arsenal and the short lived Camel Corps could be seen. Continuing along bike paths, the walk went up the northbound bridge. There are three parallel bridges across the Carquinez Straits. The two automobile spans are usually referred to collectively as "The Benicia Bridge". The 1.2 mile (1.9 km) deck truss bridge opened in 1962 as a replacement for the last automotive ferry service in the San Francisco Bay area. The 1962 bridge carries four lanes of traffic in the southbound direction, as well as a pathway for pedestrians and bicyclists. A 1.7 mile (2.7 km) bridge was built alongside and opened on August 25,2007 which carries five lanes of northbound traffic. The cost to construct the 1962 span was 25 million, and 1.3 billion to build the 2007 span. Between the two vehicle bridges is a railroad bridge owned and operated by the Union Pacific Railroad The railroad bridge was the first bridge at this location, built between April 1929 and October 1930 by the Southern Pacific Railroad. It is used by Union Pacific and Burlington Northern & Sante Fe as well as Amtrak. From December, 1879, until the opening of the Benicia-Martinez (Carquinez) Railroad Drawbridge on October 15,1930, all Central Pacific and Southern Pacific trains crossed the mile-wide Carquinez Straits by ferry between Benicia and Port Costa. After crossing to the Contra Costa County/Martinez City Limit sign, the walk doubled back and went under the bridge to the checkpoint near a scenic view area which is under construction. From here the "Mothball Fleet" was visible. This is the anchorage of the ghost, or mothball fleet, a collection of U. S. Navy and Merchant Reserve ships, created in the period following World War II. Many ships were removed for sale as scrap metal during the 1990s. Over 80 ships still remain in the bay including the WWII battleship USS Iowa. In 2010, plans were announced to remove the mothball fleet in stages, with final removal by 2017. The location also provided a clear view of train traffic on the railroad bridge. The walk then went back through the old Benicia Arsenal housing area.