The Anza-Borrego Desert State Park in California has an area of more than 500,000 acres or 200,000 ha .
With 600,000 acres ( 240,000 ha ) that includes one-fifth of San Diego County , ABDSP is the largest state park in California and , after New York 's Adirondack Park , the second largest in the contiguous United States .
Anza-Borrego Desert State Park