About the Tulsa Race Massacre. My grandfather witnessed a convoy of dump trucks loaded with bodies being dumped into the Arkansas River. That's why looking for mass graves is Tulsa's way of still minimizing the numbers. It has never been a secret among whites, and was often bragged about in the 60's as being the reason there were no race riots in Tulsa, and no desegregation! Please don't allow our GOP mayor to continue to try sweeping this under the rug!