High desert. My dad's friend killed one of the biggest bucks I've ever seen in San Diego County, north of Jacumba. They are there.
As for Mount Laguna, I spent the last 20 years hiking, mountain biking and hunting the recreation area. There will always be hunters up there. I know people think they have their honey holes but I don't believe there are any "secret" spots up there. I've seen people just about everywhere in those hills.