sentences:  Pipestone, Minnesota is the site of historic Native American quarries of catlinite, which is more commonly known as "pipestone".Another notable outcrop in the region is the Jeffers Petroglyphs, a Sioux Quartzite outcropping with numerous petroglyphs which may be up to 7000–9000 years old.Drier than most of the rest of the state, the region is a transition zone between the prairies and the Great Plains.