It most certainly is, you can see the camera data to the right and I still have the original RAW file I only added my watermark to all of my photos a few weeks ago which would explain why there isn't a watermark on the wallpaper site (If that's the case).
Do you mind if I use this for a school project? I'll be sure to give you credit and it will only be shown to my class; it won't be posted online or anything. This is the perfect picture to match one of my quotes, and I'll really like to use it!!!