American Bittern, Merced National Wildlife Refuge.
This bird flew out past my car, doubled back and disappeared into the rushes. I didn't expect to see it, but when I drove up to where it had bee, there it was, hanging out halfway up the reeds and trying its darnest to convince me it wasn't there.
At this point, I am maybe 3 meters from it. It was wary but didn't seem to be stressed, so I took a short period of time to get some images, and then got away from it so it could get to a safer place.