"A herd of 12 Bison appears at your Home City Gather Point."—In-game description
Cheyenne Hunting Grounds (Lakota Hunting Grounds prior to The WarChiefs) is a technology in Age of Empires III that can be researched at a Trading Post built on a Cheyenne (Lakota before The WarChiefs) settlement. Once researched, 12 Bisons will appear on the Home City shipment point.
Cheyenne/Lakota Hunting Grounds is very cheap and very useful, spawning huntables right at the Home City shipment point which makes them easy to secure. In The Asian Dynasties, it is also useful for the Japanese as the number of animals are enough to fill the Toshogu Shrine and then a regular Shrine as well.