Drawing on the results of interviews and access to information requests, we explore conservation officer work in two urban regions in one Canadian province ( Ontario). Specifically, we examine the work of the federal-level National Capital Commission ( NCC) in Ottawa and the provincial-level Toronto and Region Conservation Authority ( TRCA). Applying Jessop, Brenner and Jones's model of socio-spatial relations, we show how nature plays a different role in NCC and TRCA policing depending on the places their conservation officers work in, the kinds of territorial boundary maintenance in which they engage, the scaling of their activities in various jurisdictions, and the policing networks that they are part of. In assessing the place of nature in conservation officers' work, we contribute to debates about how the boundary between nature and the urban is produced through regulatory practices.