We see them heading north every evening around dusk. And I have seen them heading south just before sunrise. Hundreds of crows. It appears they are going to different overnight roust locations; sometimes all together and sometimes separately. It appeared once that perhaps a hundred gathered at Lake Merritt on the Grand Ave side; but I was unable to go visit to confirm.
We are viewing from the 6th floor of a building on the west edge of Lake Merritt.