Mission Trails Regional Park Foundation is the nonprofit steward of San Diego's 8,000-acre Mission Trails Regional Park, operating from the Visitor and Interpretive Center at One Father Junipero Serra Trail in San Carlos. Established in 1988, the Foundation works in partnership with the City of San Diego to fund capital projects, education programs, habitat restoration, and trail maintenance across what ranks as the sixth-largest municipally owned park in the United States. The Foundation's free field trip program educates more than 3,000 children annually, with most visiting to learn about Kumeyaay history at a park whose trails and canyons predate the 1542 landing of Cabrillo in San Diego Bay. Cowles Mountain—the highest point in the city of San Diego at 1,592 feet—draws hikers to the Barker Way Trailhead off Navajo Road, one of 60 miles of hiking, mountain biking, and equestrian trails that the Foundation helps maintain through grant-funded partnerships. A $2 million grant from the San Diego River Conservancy funds ongoing land acquisition in the East Elliott Community Planning Area north of State Route 52, adding more than 100 acres to the park alongside a 2022 City purchase of 25 acres. The Foundation engaged RECON Environmental for a multi-year habitat restoration and invasive species removal project targeting fountain grass, mustard seed, fennel, and floating water primrose in Kumeyaay Lake and along the San Diego River. The 14,000-square-foot Visitor Center houses a 94-seat theater screening the Emmy Award-nominated film Rise and Fall of the Mountains at Mission Trails Regional Park, produced with SDSU professor emeritus Patrick Abbott. Post-hike traffic from the Cowles Mountain and Mission Trails corridors filters into the San Carlos commercial strip along Lake Murray Boulevard, where Pure Press serves the grab-and-go crowd heading south toward the 92119 ZIP. The Foundation was named a 2025 California Nonprofit of the Year by Assemblymember Christopher Ward, and its Visitor Center doubles as an after-hours event venue for weddings, corporate gatherings, and nonprofit fundraisers overlooking Mission Gorge.