Where It All Goes Down
1976 California, 1815-1830 Maryland
There's a pretty big contrast between the two main settings of this book. But, truth be told, Octavia Butler doesn't really spend a lot of time describing her setting. She's much more interested in plot and dialogue, which is one reason why the book is so fast-paced and exciting. The closest thing you really get to a description of 1976 California comes indirectly in passages like this: "A couple of Kevin's friends came over on the Fourth of July and tried to get us to go to the Rose Bowl with them for the fireworks" (6.3.1). The mention of modern stuff like the Rose Bowl and halftime fireworks helps contrast the modern world with the old one.
When Dana travels back in time, she briefly describes the way she goes from the comfort of her home to a more natural setting, saying, "Suddenly, I was outdoors kneeling on the ground beneath trees. I was in a green place. I was at the edge of a woods" (1.10). Again though, this is really the most description of setting you're likely to find in this book. The main focus here is on time, not necessarily place.