My mother and I got into a small argument tonight which will probably never come up again, but I still want to know what the right answer is.

She claims the Ancestral Puebloans were the furthest northern reach of the Aztecs. She claims to have been to multiple lectures that have said so.

I say the Ancestral Puebloans predate the Aztec culture, and the Aztecs never really got much further north than Mexico. I think she may be confused by Aztec Ruins National Monument, which is decidedly not Aztec.

Which of us (or is it both of us) is misinformed?