Like a lot of people, I've spent a bit of time in 6A over the years. Both on archery hunts, as well as with my kids on junior hunts.
The high-level, is of course that 6A is a unit with LOTS of elk all over the place. Not one single portion of the unit is necessarily a lot better than all the rest, but there are pockets to be found....
Whether on archery hunts, or junior hunts, we like to concentrate on the quiet areas. Rattlesnake or Pine Grove offer a great opportunity to get away from roads & people to get a bit more of a 'quality' hunt, IMO.
Other than the quiet areas, I would take a look at a topo or Forest Service map and find an area with some canyons/terrain that is as far away from roads as possible. Though there are frequently elk to be seen from the roads, the best hunting is deeper in the woods. This is only my opinion of course, and we all know what 'opinions' are like!
Sincere good luck to your son though! As long as you hunt hard & smart, there is a very good chance that you'll come across a cow for him to take a shot at!
PM me your phone number if you want to chat about any other details.
S.