- Black Hills
- South Dakota landform, translating Lakhota pahá-sapa; supposedly so called because their densely forested flanks look dark from a distance.
- Pierre
- Modern French form of masc. proper name represented in Modern English by Peter (q.v.). The city in South Dakota, U.S., was named for Pierre Chouteau (1789-1865) who set up an Indian trading post here in 1837.