The Grindstone family climbs down an embankment that leads to the Moreau River on their family land on the Cheyenne River Reservation, a sovereign Lakota Nation within the state of South Dakota. Mona Grindstone, second from right, has received both doses of the vaccine while her husband Earl, right, has so far chosen not to get the vaccine. Since the arrival of the Covid-19 vaccine early in the year, tribal leaders and members have been navigating differing opinions about its effectiveness, safety, and trustworthiness. March 2, 2021.