This chapter examines the ways in which North American indigenous authors have engaged the entanglement of American anthropology and ethnography, science fiction, and the American Indian/First Nations to imagine Indigenous futures, using the work of Craig Strete, Celu Amberstone, Cherie Dimaline, and Rebecca Roanhorse as case studies. Joining twentieth and twenty-first-century Indigenous anthropologists, these authors critique anthropological conceptions of “a culture” as a bounded, synchronic, structured “whole” available to be “known” by the expert anthropologist—a form of knowledge that satisfies settler colonial needs to define, control and often erase Indigenous peoples. Instead these Indigenous futurists engage to varying degrees in what Audra Simpson calls “ethnographic refusal,” the exercise of Indigenous sovereignty through the refusal to satisfy the non-Native audience’s need to “know.” Centering instead Indigenous knowledge systems, these narratives challenge the Western categories around which ethnography and science fiction has been traditionally organized—linear concepts of time/teleologies of “progress,” the distinction between “reality” and “story,” the everyday and the mythic, “science” and “fiction”—and in the process challenge the genre of science fiction as such. “Culture” in these texts becomes an active process of transmission and tutelage that asserts Indigenous sovereignty and futurity.