It appears the bear may have considered that pocket his spot and you were the intruder. If the charge would have been for real and not a bluff, it could have turned out bad. If you don't already, consider carrying a defensive weapon when visiting those areas.
No carry weapon would be necessary if people didn't feed, attract, and train the bears to food. Bluff charges and real charges wouldnt occur if people would stop feeding and training them. This is 99% of the cause of human and bear problems today.
15 years ago this almost never happened. If a bear saw or winded you it was gone. Bear were more afraid of people than deer were. That is no longer the case. We used to camp without having to worry about keeping our food scent out of camp. Now you better get all the cheeto’s off your fingers before you get in you’re sleeping bag.
Only thing that I had in the area was trophy rock and it was on the stump. No corn or any other kind of feed. just fyi. According to my cams they don't seem to like the trophy rock as much as the deer do (so far anyway). But they do like playing with it (knock it off the stump) like they do my trail cams.
I believe it was about a 100-130 lb sow that had little ones up a tree near by that you scared going in and didn't see the little ones. plus I AGREE WITH KYLE IT HAS LOST IT'S FEAR OF HUMANS!!! REASON UNKNOWN. Probably watches you come in and out and decided to protect its block of mineral as a food source.