The Osage Indian murders were a series of murders of Osage Indians in Osage County, Oklahoma in the early 1920s, called the "Reign of Terror" by newspapers. Estimates are that 60 or more wealthy Osage were killed from 1921 to 1925. The murders appear to have been caused by the greed of white men for the great wealth of the Osage, whose land was producing valuable oil and who each had headrights that earned lucrative annual royalties.