Morgan Territory Regional Preserve is a regional park in Contra Costa County, California. Located east of Clayton and north of Livermore, California, bordering on Mt. Diablo State Park, it is part of the East Bay Regional Park District (EBRPD). The preserve was founded in 1975 with fewer than 1,000 acres (400 ha), but EBRPD has gradually acquired more property, and, since 2015, the preserve encompasses 5,230 acres (2,120 ha). The main access roads run from Livermore and Clayton.