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