green meadow and bermuda buttercup flowers in don edwards wildlife refuge, dumbarton bridge in the background, fremont, san

america area background bay baylands bermuda buttercup blooming blue bridge california clear delta don edwards dumbarton east flowers fremont grass green landscape levees marsh meadow natural outdoors park plants ponds protected refuge restoration rocks san francisco scenery scenic shoreline sky slough south spring sunny sunshine swamp united states water waterways wetlands wild wildflowers yellow