The Western Mexico shaft tomb tradition refers to a set of interlocked cultural traits found in the western Mexican states of Jalisco, Nayarit, and, to a lesser extent, Colima to its south, roughly dating to the period between 300 BCE and 400 CE, although there is not wide agreement on this end date. Nearly all of the artifacts associated with this shaft tomb tradition have been discovered by looters and are without provenance, making dating problematic. The first major undisturbed shaft tomb associated with the tradition was not discovered until 1993 at Huitzilapa, Jalisco.