Benjamin Madley is a historian at UCLA, but he's a child of far Northern California. His exposure to the Karuk people and homeland spurred his interest in Native America, colonization, and genocide.
Madley's first book is An American Genocide: The United States and the California Indian Catastrophe, 1846-1873. It lays out in detail what happened to the original people of California.
He shares some of the details in this interview.