This chapter begins with a broad overview of the field of border studies from the 1980s to the present. It traces the roots of U.S.-based border studies from Gloria Anzaldúa to the present, paying special attention to major trends and intellectual shifts in the scholarship. It then uses a passage from Efrén Divided to demonstrate three different conceptualizations of the border in literature and delves into the way borders have been theorized in literary studies. Following this discussion, the chapter considers what can be gained by bringing Indigenous studies and border theory into conversation, especially where concepts of sovereignty, mapping, and settler colonialism are concerned. To that end, it turns to Empire of Wild to explore the useful plasticity of border theory.