Faded2,
Your description is too general. I was at the hot springs yesterday and there were several persons there that match your description. At the Squint's ranch which is now the Arrowhead Regional Airport there is cell phone coverage on the hill tops. You are talking about a 7-9 mile hike depending upon which trail entrance he used.
You remind me of my parents when I got big enough to explore interesting places. Try to not be too concerned about his survival abilities. There is a lot to see and explore on his trip. I am sure he will have a lot to talk about when you see him.
Good luck with that !