These are all classic steps in the march toward mass murder, with clear echoes in later genocides. In 1851, California’s governor, Peter Burnett, said that he expected “a war of extermination” to continue “between the races until the Indian race becomes extinct,” and Senator John Weller later said that “the interest of the white man demands their extinction.” Toward that end, California spent the equivalent of $45 million in today’s money on two dozen state militia expeditions that murdered at least 1,340 California Indians, according to Benjamin Madley, a historian at U.C.L.A. and the author of “An American Genocide: The United States and the California Indian Catastrophe, 1846-1873,” whose work I am heavily indebted to. The Army and its auxiliaries killed a minimum of 1,680 more, and vigilantes murdered at least 6,460. Congress reimbursed California for most of that money, retrospectively endorsing genocidal campaigns.

In 1860 in Humboldt County in Northern California, for example, an estimated 150 Wiyot women, children and elderly men were murdered. According to a newspaper reporter who saw the aftermath, “Lying around were dead bodies of both sexes and all ages from the old man to the infant at the breast. Some had their heads split in twain by axes, others beaten into jelly with clubs, others pierced or cut to pieces with bowie knives.” By 1880, some 20,000 Native Californians remained. “It is not an exaggeration to say that California legislators established a state-sponsored killing machine,” Professor Madley said.

The Miwok of Yosemite lived nearly every chapter of that history. For millenniums, thousands occupied small towns in the valley that at least some of them called Ahwahnee. In the early 19th century, a pandemic greatly reduced their numbers, and survivors fled across the Sierra Nevada to live with the Mono Paiute people.