Contribute a photo Grassmont Reservoir San Diego County, CA Follow Share Share Grassmont Reservoir... Email Facebook Twitter Grassmont ReservoirFollow Overview Fishing Reports Guides & Tackle California Grassmont Reservoir Nearby Businesses Guides & Tackle Shops near Grassmont Reservoir Checkout local fishing businesses near Grassmont Reservoir. Add your business. Currently, no businesses are listed for Grassmont Reservoir. Be the first to add yours! Feature your Grassmont Reservoir Business here! Learn more