My Son found this bug in the back yard. It kind of looks like the Coreid Bug or Leaf Footed Bug shown on your web page, but it has an arched back. We seen it on October 11 and we live in South Central Pennsylvania.
You are close. It is a true bug, but not a leaf footed bug. You have found a Wheel Bug, Arilus cristatus, a member of the Assassin bug family Reduviidae. These are predators that eat other insects, sucking them dry. Some species are able to bite humans with their piercing/sucking mouthparts. Many species will inflict a painful bite if carelessly handled. The Wheel Bug gets its name from the semi-circular crest that terminates in spurs and resembles a cogwheel. The species is fairly common.