I've been going through the same thing, been stalking a 4 plus year old Boar. He is pretty unpredictable and seems to be really canny to have survived this long. I've seen his sign. And spotted an area he regularly visits near a group of small hobby farms and large truck gardens. He keeps jumping the border between the next village (county) and my counties forest preserve. I need different permissions hunt both.

I've spotted him twice, once months ago in an Oak woods (eating Acorns) and lately in the woods near the farming area. He has what looks like a long bullet scar on his left flank. Probably why he has survived so long, he learned the hard way.