Complex sentence: The Blackfoot tribes were a traditional buffalo culture until the failure of the buffalo hunt in 1883, because of non-native overhunting, led to the "Starvation Winter" when 600 natives died.
Split into simpler sentences: The Blackfoot tribes were a traditional buffalo culture until the failure of the buffalo hunt in 1883 as a result of non-native overhunting. This led to the "Starvation Winter" when 600 natives died.