In my neck of the woods, a stand about every 40 acres is as close as you'll ever need them.

However, keep in mind this is the number of stands, not the number of hunters. This same land can only handle a harvest of 2-3 mature bucks per section, not 16. If there were a hunter in every stand, and every hunter shoots a buck, they'd be shooting nothing but yearling bucks by the second season.