This photo has some flaws. The lighting is a bit off. The picture is a little bit blurry. Ideally you'd want a little bit different angle to show off the snake's head better. But no complaints from me. I wasn't thinking about zone rules or mixed lighting at the time, my thoughts were don't take my eyes off of the snake, be careful of any other snakes that might be around and try to get a picture of a rattlesnake while not taking my eyes off of the snake. My first rule of photography is generally to avoid dying for the sake of a photo. Unless maybe it was a real nice photo of a bear amid some wildflowers with Rainier in the background; that one I'd have to think about.

You can see the creek in the upper right which had the snake pinned in and forced him to take an aggressive defensive posture. Rattlesnakes raise their head up and can strike a foot or two in the air but not really much farther. They shake their tail to scare you away. I heard the tail rattle before I saw the snake and immediately looked down. As long as you don't step on one then it probably won't bite you. Rattlesnakes are not found in Western Washington as far as I know but they are found in Central and Eastern Washington which is more similar in climate to some desert areas.