Round Valley Regional Preserve is a regional park just outside Antioch, CA and Brentwood, CA that is part of the East Bay Regional Parks (EBRPD) system. It is on Marsh Creek Road, approximately 5.2 miles (8.4 km) west of the intersection with Vasco Road. The park was begun in 1988, when Jim Murphy sold 700 acres (280 ha) of land to EBRPD. The land originally belonged to Mr. Davis' grandfather Thomas Murphy, an Irish immigrant, who had purchased the land in 1878 for a farming and ranching operation. The preserve has since expanded to encompass 1,911 acres (773 ha).