Readers comprehend natural vitality from Willa Cather’s prairie trilogy: O Pioneers! (1913), The Song of the Lark (1915), and My Antonia (1918). Nebraska’s rough, but pristine beauty and pioneers’ vestiges on the plains attract readers to her novels. Cather, in particular, unravels the western frontier through the lives of women who are determined to reclaim native soils. For that reason, scholars in general have investigated the relationships between the western environment and female protagonists. This approach is effective in interpreting space per se, but it is also a major requisite to understand time from Cather’s literature, in that one’s experience is able to be thoroughly represented by the integration of time and space together. In this essay, I explore how Cather understands her times and represents them in her prairie trilogy. First, I examine the ways in which the female writer employs the railroad as a metaphor in her novels. Describing the dynamic movement of the locomotive that runs on the plains, she explains a futuristic image that settlers perceive from the modern technology. Second, I argue that Cather uses the prairie environment not only for a spatial object but also for a temporal concept. She presents the prairie environment as a holistic integration of time and space by chronicling the decades during which female protagonists transform the primitive plains into a rich farm community. Against East Coast elitism that maintained Anglo-Saxon urbanity as national identity in the early twentieth century, Cather finally suggests the frontier as an alternative American consciousness throughout her prairie novels. (Inha University)