This article looks at the shifting Argentine policy towards immigrants, the role of immigrant settlers in the Patagonian frontier, and challenges presented by large immigrant colonies of areas of contested sovereignty. Argentina encouraged tran-Atlantic immigration in the late nineteenth century to populate the country, including the newly incorporated region of Patagonia, which was formerly controlled by independent indigenous groups. Immigrants moved to the frontier as part of a staged migration, and quickly occupied key economic and social position in their growing towns. Their success on the frontier put Argentine authorities in a difficult position: they relied on immigrants to develop Patagonia, but they remained uncertain of the allegiance of those same immigrants. This difficult position was exacerbated with regards to Chilean immigrants, who were seen as "less preferred" than European immigrants and represented a heightened seditious threat, since Patagonia shared a long border with Chile. This article argues that the ambivalence by the state towards immigrants, the semi-colonial administration of the frontier by the Argentine state, and the immigrants own economic and social prominence created the conditions for the emergence of a civil society in northern Patagonia. This civil society grew in response to police abuses, and became adept to using institutional allies outside of Patagonia (like cabinet officials and diplomatic staff) to attempt to control local officials.