As a one time interpretive guide at the Gila national monument in New Mex, a puebloan, Mimbres cliff community, I was able to pick up a few 'trade secrets', as it were. Its pretty much confirmed that a good amount of trade existed between meso-america and the S.W. US, namely with the puebloan ancestors like the Anasazi, Mimbres, and Hohokam. The god Tlaloc can be seen in a number of pictographs in the area, of which I have seen personally. This God originated in Meso-America. A moccasin from the great lakes was found in the Gila site.
And, while I've found no accounts of connections between the mound builders of mid US and Meso-america, Its hard to fathom that one didn't to some degree exist. The Mississippi river is a highway right down to the Gulf, and from the the Caribbean and the Mayan shores of Guatamala, not to mention Veracruz, an Olmec center. Could very well be that either their trade goods have decayed or simply haven't been found. BTW, corn is a highly complex plant that was systematically 'genetically engineered' by the early meso americans. This Maize then spread, well pretty much all through the americas... certainly by trade.