Complex sentence: In 1878 he was appointed US Agent at the White River Indian Agency in western Colorado, and was killed by Utes the next year in what became known as the Meeker Massacre, part of the Ute War.
Split into simpler sentences: In 1878 he was appointed US Agent at the White River Indian Agency in western Colorado. The next year, he was killed by Ute warriors in what became known as the Meeker Massacre, part of the Ute War.