I still need some advice from you folks with National Forest roads, or stuff like the Great Divide, gravel roads. Big hills sometimes, maybe steep, bigger rocks, and such. For the Katy and other rail-trail a decent light & fast road touring bicycle with wider tires will probably work well.
I saw the bicycle of the guy that won the Great Divide race. It looked like a mountain bike with very shallow drop bars, and a bike packer set-up. I'll listen to you about a small backpack, but you'll have to drag me there kicking and screaming. I'll also check in with the local off road group.
I do appreciate your advice.