I really like the way the sunlight highlights the single tree in this shot so even though it violates the rule of thirds, I wanted it in my Grand Canyon photo collection. I considered cropping out the rock on the right but decided to keep the full. frame This may be a Ponderosa Pine.
Elizabeth, Jane gave you good advise. Even with that bright rock your composition worked very well. Seems like you picked a good time to break the rule of thirds. What a wonderful place you are getting to photograph.