The original photo does seem a bit constrained but I have an emotional attachment to the subject so the flaws aren't as obvious to me.
I'm late to the party here but I know and love that area too. I always wondered about the name and always figured it was a single horse used as a landmark somewhere. It sounds like the truth is quite a bit more grisly.
That road down on the canyon rim is the White Rim Trail which was build by uranium prospectors in the 1950's. It can be traveled as a 105 Mile loop and I've done it by mountain bike a number of times. The most fun is to do it as a three day trip, camping along the way but some of my more hardcore cyclist friends prefer to do it in a single day which requires a 4am start and a very long day on the trail for me!
I think this first shot of Keyhole Arch may be in the OP's photo.