Willa Cather often earns attention from environmental literary scholars for her beatific and nostalgic depiction of "the frontier," though in this ecocritical study, I argue that Cather presents a unique, multi-faceted evolution of America's frontier and claims it, once again, as a physical place that deserves salvaging. From 1913-1925, Cather worked within Frederick Jackson Turner's frontier rhetoric, yet she moved America's frontier from a physical landscape of the past to a frontier-of-war in France and finally into the home. With O Pioneers!, Cather offers a nostalgic view of life in Nebraska, though she rejects Turner's creation of a strictly masculine frontier. In One of Ours, Cather explores how feminized characters might exist on a frontier-of-war, but she concludes that such a frontier perpetuates violence and the destruction of art. Writing The Professor's House, Cather offers one more solution to reopening Turner's closed frontier: the home. Working to reopen the frontier on a physical plane rather than a metaphorical one became important to twentieth-century Americans, as it meant the continued development of a unique American character. Beyond humanity though, rediscovering the frontier in any capacity gives power back to the physical environment, and empowering the environment becomes a step toward treating it with respect and seeing it as something worth our care.