||There is a trend in literary criticism that has persisted well into the twenty-first century - a tendency to distinguish certain American literary movements as belonging to either men or women. Two genres have been treated this way more than most: naturalism (which has been called masculine) and regionalism (which has been called feminine). Historically, these movements emerged side-by-side. In the 1890s and early 1900s, naturalism supplanted the regional movement known as "local color" as America's ascendant literary modality. For this reason, the naturalism marks a shift in American culture that can be read as a masculine rebellion against a feminized art form. It is my argument, however, that this is a reductive conclusion that deserves further exploration here. Accordingly, this project shall look at the way three women writers engaged with naturalism in their writings, these authors being Edith Wharton, Willa Cather, and Eudora Welty. I have selected these three because each authored texts that explore not only the concerns of naturalism but also those of regionalism. Each text to be explored shall therefore undo previously constructed distinctions that pose naturalism against regionalism and, in turn, men's fiction against women's fiction. I shall set the stage for this primarily by destabilizing naturalism as we know it, arguing that it represents an era in literature that was concerned not merely with masculinity but with gender in general and, specifically, with the way the human body was being rearticulated by evolutionary and deterministic discourses as something more malleable and adaptable than humans had before realized.