areas I personally hunt have always had multiple mineral sites and by that I mean many sites, one farm I have hunted for over 30 years, 120 acres approx. has a dozen mineral sites and they all get used, a lot from March to August maybe September. My thinking has always been the more mineral sites, even though IMO, they are used more when hunting season is not open, but still used a good bit of the year, the more mineral sites I have the more likely deer will make that their core area. I have never really had them for the purpose of hunting over them, but to attract and maybe hold deer from march til august, and hoping the deer like the many mineral sites and find a home.
On the 800 acres I hunt in KY, I keep 25 -30 mineral sites going, that is why I go see the salt man every couple years and get a half pallet of trophy rock.