I don't normally find beetles in my back yard, but this one was so large, it attracted my attention. I'm pretty sure it's a Horned Passalus, but would like some confirmation. One thing to help in identification - it was moving out of a good angle for a photograph, so when I picked it up to move it back on the flat surface for a better picture, it emitted a kind of "hissing" sound. And, although it can't be seen very well in this picture, it had hairy middle legs.