That's a Pac. Northwest deer for sure - it's got moss hanging from its antlers!
Greg, you will know pretty soon if the deer are raiding your garden. As the weather cools off they move down from the higher country, especially when it's been such a hot, dry summer as you've had. Not a lot of lush green growth later in the summer, means they will pursue the irrigated garden goodies that will stay around longer, at lower altitudes.
You can start using scent deterrents to keep them away - things like hair from your hair brush and old pairs of stinky sneakers that you can't wear any more. You can also buy different scent deterrents from HD and Lowe's that are specifically formulated against deer but will also keep away things like bunnies.
Got to have been something pretty hungry and determined to eat the whole sunflower - but deer are very fond of roses, too. Got a GoPro so you can video the garden? How about motion-detector lights outside? That's what I have to alert me at night when the raccoons are in my garden. The lights come on and I go out and behave like a demented person, waving, clapping, growling and barking. I'm sure my neighbors think I am really nuts.
