I vaguely recall that some circus bears were of a Eurasian origin and their genes may persist in some non-AZA "Game Farm" populations, but I'd guess that most North American Brown Bears displayed in the United States are strictly mainland and Kodiak Island bears. Someone on Zoochat proposed an Otter Themed Exhibit in which the word's otter species could be displayed. The world's bears would also make a good comparative exhibit. Brown Bears would especially (Grizzly, Kodiak, Kamchatka, Hokkaido, Himalayian, Syrian, and western Eurasian) interesting given the regional variations. At least as diverse as Tigers.