Lyndon, you're on a path (yes, pun) that you'll never regret. Exposing your son early and often to the wonders of nature and the backcountry will pay huge dividends down the road. We started our daughter at age 3 with a ramble in Death Valley and by the time she was 10 she had seen almost every major national park between the Rockies and the Pacific. She was breathing the rarified air of her first fourteener at age 8, and had her own harness and rock shoes by age 11. She's 15 now, and certainly has grown other interests, but she still gets fired up for our annual trip to the Sierra.
As long as you're patient with his pace and constant desire to divert and explore, especially early on, you'll build a solid foundation for a lifelong love of the outdoors. It was very hard for me initially to stop so often when Brianne was young, but you've gotta allow kids the space to have their adventures. They build a lasting passion for hiking on their terms, and sometimes it's a very fine line you have to walk with what you might feel is necessary versus what your child sees as mandatory. Those two things will slowly merge over time, but for now your son's whims should be indulged as often as possible on the trail.
One suggestion: if you don't already, make a lightweight, collapsible tripod part of your everyday gear and use it to take family shots as often as possible. Looking back now on 15 years of family photos, I find that many of our most memorable family pics were taken this way, especially in national parks or the backcountry when there is no one else around to hand the camera to.
You're beginning a great, rewarding journey with your son. When those difficult teen years come around, this could be the foundation that helps smooth out what might otherwise be a bumpy ride.
