In the early 20th century, an oil rush in the Osage Nation, located in Oklahoma, produced a torrent of oil revenues for the Native American tribe, making them the richest people per capita in the world. But their wealth invited greed, exploitation and murder on the part of white "guardians" who came to control the Osage's money, and would lead to the first major investigation by the FBI. In this "Sunday Morning" story originally broadcast April 30, 2017, correspondent Lee Cowan talks with David Grann, author of "Killers of the Flower Moon," about the reign of terror against the Osage.

"CBS Sunday Morning" features stories on the arts, music, nature, entertainment, sports, history, science and Americana, and highlights unique human accomplishments and achievements. Check local listings for CBS Sunday Morning broadcast times.

Subscribe to the "CBS Sunday Morning" YouTube channel: http://bit.ly/20gXwJT
Get more of "CBS Sunday Morning": http://cbsn.ws/1PlMmAz
Follow "CBS Sunday Morning" on Instagram: http://bit.ly/23XunIh
Like "CBS Sunday Morning" on Facebook: https://bit.ly/3sRgLPG
Follow "CBS Sunday Morning" on Twitter: http://bit.ly/1RquoQb
Subscribe to our newsletter: http://cbsn.ws/1RqHw7T
Download the CBS News app: http://cbsn.ws/1Xb1WC8
Try Paramount+ free: https://bit.ly/2OiW1kZ

For video licensing inquiries, contact: [email protected]