10/18-19 Tuesday and Wednesday mornings. I went for a walk/jog at the salt marshes of Alviso in south San Francisco Bay, part of Don Edwards San Francisco Bay National Wildlife Refuge. An official trail map can be found here. This is where my route is devised (two trips). I highlighted where I went using green overlay color. 
Highly recommended for dawn and dusk, not just for better color, and probably more active birds, but also because there's no shade in the whole area: marsh and mud. You can bring a canoe here. Or just walk. Not crowded. I saw one person each day. I would avoid this in the summer months: there might be sewage smell, and probably mosquitos.
I was in the vicinity for work. I headed out at ~7:30am, nice crispy weather. Should leave earlier. I came back at 9:00 the first day, and 9:45 the 2nd. By 8:30, it was already getting too sunny. I mostly walked, a little jogging. The mud caked onto my soles. Hard to run where the mud flies off your shoes from time to time. Saw many birds. Most noticeably egrets. They are big and white, and standing right in Alviso Slough where the train track and road cross it: very close to my hotel. Groups of pelicans further out. They fly overhead from sometimes. Many black necked stilts, whose neck isn't all black, avocet. Lots of little birds and gulls. First day, I walked mainly along Alviso Slough. Whenever I walk by bushes, I could hear rustling sound. Saw a chickadee size black bird with white belly. Not sure what it is.
The 2nd day, I went to the NWR education center (further away). It was not open yet when I arrived. Nice boardwalk there. Quite a few benches here and there. 
There's a shelter with picnic tables. More land area and mud. Saw two rabbits. Lots of pelicans. The green marsh area on the map is half water. Those salt ponds are really ponds, separated by dikes of mud. The "Trail Connection" is real. That's the only place you can go from one side of the train track to the other, because instead of one dike, there're three separated by ditch of water. On the dike, each step is triggering hundreds of little flies to jump up for a few inches, and settle down again. Feels like walking in low gray clouds. Strange.A good workout, nice scenery.
