In the 1960s the open space of the mountain was threatened with suburban development expanding from the surrounding valleys. In 1971, when MDSP included , the non-profit organization Save Mount Diablo was formed and open space preservation accelerated. MDSP was the first of twenty-nine Diablo area parks and preserves created around the peaks, today totaling more than . These Diablo public lands stretch southeast and include the Concord Naval Weapons Station, Shell Ridge Open Space and Lime Ridge Open Spaces near Walnut Creek, to the State Park, and east to the Los Vaqueros Reservoir watershed and four surrounding East Bay Regional Park District preserves, including Morgan Territory Regional Preserve, Brushy Peak Regional Preserve, Vasco Caves Regional Preserve, and Round Valley Regional Preserves. The new Marsh Creek State Park (California), formerly known as Cowell Ranch State Park, and Black Diamond Mines Regional Preserve, are among the open spaces stretching back to the north. In this way the open spaces controlled by cities, the East Bay Regional Park District, Mount Diablo State Park, and various regional preserves now adjoin and protect most of the elevated regions of the mountain.