This Dissertation uses “Green Lines” as a type of Zionist environmental legacy—vision, reason, practice, and expertise, and as an analytical perspective, to explore Zionism as an eco-Hegemony. In the four chapters of the dissertation, I explore how a vision of “Green Lines” shaped two important development projects in two key moments and sites in Israel’s environmental history. The first, the Hula Drainage project in the north of Israel, during the 1950s and the 1960s, and the second the formation of the Wine Route in the Negev/Naqab highlands in the late 1990s and the early 2000s. I argue, that in each of these moments the vision of Green Lines that is deeply rooted in colonial understanding of nature and of nature management, worked as powerful terrain, articulating development and conservation, visions and practices, to support the Zionist hegemony as an ethnic project. It produces and solidify differences and boundaries between Jews and Arabs, and Judaize what is considered as good ecology and good environmental practice. Drawing on scholarship in critical geography and historical political ecology, I employ the concept of “Green Lines” analytically as an alternative to previous scholarship on Palestine and Israel which often analyzed Palestinians, Bedouins, and Jews in a way that separates the histories and societies of these specific social groups, and the histories of these social groups and nature. In this dissertation I focus in particular on the ways historical visions of Green Lines, are reworked into present political economies, and ecological understanding of drylands, and form struggled-over social ecologies where the meaning of good healthy ecologies, environmentalists, and environmental expertise are contested.