'46-'48, or fight it in the courts

The Treaty of Guadalupe-Hidalgo that ended the Mexican War during James K. Polk's  Presidency, still making for crazies, after all these years;

Lawyers for a billionaire landowner who closed a popular surfing beach told a San Mateo County judge on Thursday that the Silicon Valley titan did not violate public access laws and in fact had every right to block beachgoers from trespassing on his property.

The argument came on the first day of a civil trial over the public's right to access a public beach. The Surfrider Foundation has accused venture capitalist Vinod Khosla of flouting the California Coastal Act when he blocked the only road into Martins Beach, a sandy, 53-acre haven along the coastal cliffs about 6 miles south of Half Moon Bay.

Khosla, one of the founders of Sun Microsystems, can afford this legal battle, and has in fact already won a skirmish;

A San Mateo County judge ruled in October [2013] that the Treaty of Guadalupe Hidalgo, which ended the Mexican-American War in 1848, allows Khosla to exclude the public. The treaty essentially required the United States to recognize Mexican land grants, and the judge found that such a grant existed on Martins Beach. 

Rights that had been recognized as existing for well over a century before California tried to eliminate them by state legislation in the 1970s with the California Coastal Zone Conservation Initiative. But only billionaires can afford to exert their rights in the 21st century.