Just thumbed through the Black Bear section of the 2011, 13th edition, Boone and Crockett all time list (21"+) and found 5 Washington state entries, and 2 Idaho entries. Its interesting how even in places that have the monster bodied bears you'll see many with the body but not the skull. In some other places I've seen pictures of bears just over the 6' mark that delivered a 21" skull. Bottom line you could put in a lot of time, in an area represented well in the book, specialize in shooting big bodied bears and never break the 21" barrier. The biggest Black Bear I ever heard of was an 8'11" (if my memories working right) inch monster in one of the NRA magazines. Some discrepancies in where it was actually shot vs where it was tagged. I think its the second place entry, entered by the Pennsylvania Game Commission. Its listed at 23 7/16, number 1 is 23 10/16 from a pick up in Utah. For a place that I don't usually think of as good bear country, Utahs 12 entries impresses me. A fully mature whitetail is on its last legs at the 9 year mark, a black bear is just starting in to his prime. He'll likely live twice as long, with the possibility of 3x not totally out of the question. Stacking those extra years with added experience makes a mature boar as difficult to bag as any. Coupled with the scarcity of BC bear in any environment, and I believe its the most difficult of all species to put one in the book.