The following excerpt is from an article best read at the site (lots of photos, multiple pages):
Humans were hunting mastodons in Mexico 250,000 years ago. This archaeological heresy is supported by finding at Hueyatlaco.
Hueyatlaco is an archeological site in Valsequillo, Mexico. Several potential pre-Clovis localities were found in the 1960s around the edge of the Valsequillo Reservoir, Mexico. One of these localities is the site of Hueyatlaco. This site was excavated by Cynthia Irwin-Williams in 1962, 1964, and 1966.
One of its early excavators Virginia Steen-McIntyre writes “Hueyátlaco is a dangerous site. To even publicly mention the geological evidence for its great age is to jeopardize one’s professional career. Three of us geologists can testify to that. It’s very existence is blasphemous because it questions a basic dogma of Darwinism, the ruling philosophy (or religion, if you will) of the western scientific world for the past 150 years. That dogma states that, over a long period of time, members of the human family have generally become more and more intelligent. The Hueyátlaco site is thus ‘impossible’ because Mid-Pleistocene humans weren’t smart enough to do all that the evidence implies. Besides, there is no New World anthropoid stock from which they could have evolved.