From the review:
It turns out that history—the official American version, at least—had also lost touch with the descendants of Sand Creek’s victims, members of the Cheyenne and Arapaho tribes, who not only knew where the site was but had formal committees dedicated to memoralizing what had happened and visiting the site. This sets up the major, but by no means only, conflict in creating a new memorial: federal representatives, including scholars at state universities, members of the National Parks Service, and state and federal legislators decide that an extensive search and new memorial is called for. The Indian tribes on whom they call for help, however—represented primarily by Laird Cometsevah (chief of the Southern Cheyenne) and Steve Brady, head of the Northern Cheyenne Crazy Dogs society and Sand Creek Massacre Descendants Committee—are suspicious of the federal government. They are also amused by the feds having “lost” the site. Despite their suspicions, they agree to help “find” it and cooperate in establishing a National Historic Site because, as it happens, the tribes are pursuing reparations that had been promised but not fulfilled, and they hope that establishing a federally-recognized site will further that process.