This article explores the strategies implemented by Spanish colonial authorities on their northern border, which aimed to pacify and evangelize the most warlike indigenous groups. However, ecological challenges, the great distance from centers of political and viceregal power, constant conflicts over land and hunting grounds, and, above all, the undeniable capacity for resistance and negotiation of indigenous groups prevented Spanish penetration into the region, maintaining fragile control over some areas, achieved more as a result of negotiations than by force.