Reddit mentions of An American Genocide: The United States and the California Indian Catastrophe, 1846-1873 (The Lamar Series in Western History)

Nope. Local and State-level California and Oregon governments made laws paying out citizens for native scalps. Commodified slavery was à la mode in California especially but the entire West well into the 1900s (but since Indigenous folks were "less than human savages" it was not considered slavery in many ways. The encouragement and wholesale slaughter of entire towns, villages and countries amounts to genocide after genocide after genocide, and by genocide definitions (the various ones), the ongoing sterilisation of women, seizure of children and displacement of populations aligns itself to being "genocide" in 2019