When the federal government closed Castle Air Force Base in Merced County in the 1990s, the dilapidated buildings and vast expanse of aging tarmac left behind seemed more like a liability than an opportunity. But by 2018, the old runways that once carried B-52 bombers had found a new and unexpected customer: Google, which was testing its experimental self-driving vehicles there, far from the prying eyes of Silicon Valley. At the urging of then-state Assemblyman Adam Gray, California gave Merced County 6.5 million that year to expand the self-driving testing program at the old base. A few years later, Gray invested there, too. In 2022, a company in which Gray is a minority owner bought four apartment buildings on the former base from Merced County, according to a Times review of business filings, property records and Gray's financial disclosures.