Káto-yí-six, or Sweet Pine Hills, is the Blackfoot name for what is now known as the Sweetgrass Hills. The Hills have many distinct geological, biological, cultural and spiritual histories. This place is of significant traditional historical value to First Nations People of the surrounding prairies of what is now Montana, Southern Alberta and Southern Saskatchewan. The Sweetgrass Hills captivated author Johan F. Dormaar in 1971, and he spent over 40 years exploring and researching them until his death in 2011.