I first thought this was a leaf and was glad I didn't step on it as it lay (stood?) on the horse arena footing. When I reached down to pick it up, it immediately climbed on my finger. It didn't seem particularly anxious to leave when I coaxed it onto a board in the barn. The body is about 1.5 inches. Since it didn't spread its wings, I'd only be guessing that the span is 3" give or take.
Any of you insect experts have any additional information or ID to impart?