If nature is socially constructed, how do cultural producers construct it? Few social spaces materialize social constructions of nature as powerfully and as directly as parks, which represent cultural beliefs about nature’s form and function. This paper considers how landscape architects and other social actors involved in creating contemporary urban park landscapes think about nature and decide how to represent it through cultural objects. Drawing on the analysis of three case studies – New York’s High Line, Chicago’s Bloomingdale Trail/606, and Houston’s Buffalo Bayou Park – I consider the aesthetic judgments that cultural producers make about nature when designing and placing value on park landscapes. I find that in the cultural conditions of the twenty-first century, three aesthetic judgments prevail, converging to create a particular vision of nature that is both highly valued and tightly linked to racialized currents of cultural and economic capital. These aesthetic judgments prize nature as local, wild, and imbricated with urban space. They structure what I term “environmental authenticity”: the idea that socially valued forms of nature are rooted in classical understandings of a socially unmediated, nonhuman nature whose agency in creating landscapes is minimally violated by obvious human cultivation and that exists, seemingly organically, in postindustrial settings. Judgments about environmental authenticity, I argue, are centrally about who has the power to shape landscapes.