Centennial (1978) 4/12 For as Long as the Waters Flow

Mercy is sent to negotiate a treaty with the Indians. Zendt goes in place of McKeag. Three men heading to the new mines to work, meet up with Hans Brumbaugh, a German farmer from Russia. As they're panning for gold, two of them decide to shoot some passing Indians for their supplies. Jake says 'they killed two of us, so two white people must die'. The U.S. starts to change terms of treaty the Indians signed.

Centennial is a 12-episode American television miniseries, that aired on NBC, from October 1978 to February 1979. It was based on the novel of the same name by James A. Michener, and was produced by John Wilder. It follows the history of the area of the fictional town of Centennial, Colorado, from 1795 to the 1970s

The miniseries was one of the longest (26½ hours, including commercials) and most ambitious television projects ever attempted at the time. It had a budget of US$25 million, employed four directors and five cinematographers, and featured over 100 speaking parts spanning 26 hours of television viewing time.
https://en.wikipedia.org/wiki/Centennial_(miniseries)