 The Tarascan Empire blocked Aztec expansion to the northwest, and the Tarascans fortified and patrolled their frontiers with the Aztecs, possibly developing the first truly territorial state of Mesoamerica.Due to its relative isolation within Mesoamerica, the Tarascan state had many cultural traits completely distinct from those of the Mesoamerican cultural group.It is particularly noteworthy for being among the few Mesoamerican civilizations to use metal for tools and ornamentation.