Could have.
http://www.joebobbriggs.com/vegasguy/vg20010924.html . The guy who manages the casino is quoted here: "One reason he's been held back so far is that, when they broke ground for the hotel, Indian artifacts were discovered, leading to what has now become the largest archeological dig in the United States. "It cost $16 million to do the dig," he says amiably, "and we paid for it. Apparently this area was originally a Native American market, where the Indians gathered to trade. They're finding a lot of chirt stone, which was used to fashion tools. Other artifacts."
This is not only a major regional center, there have been numerous informed estimates made of how many points and other items there are in the area and each time it goes up another few million. This was apparently a "flint factory". My own guess is that this is the secret the Shawnee at the Falls on the Ohio used to stay rich ~ they traded their points all over the continent.
So, how about other "flint factories"? Are there any besides this one we don't know about and how old are they? How old is this one? Currently it's an active archaeological site, and my guess is they are going to keep digging and it's all the way down to the same sort of dates we see in the above article.
BTW, this site was officially discovered some time in the 1990s. I knew about it (more or less) from a cousin who regularly collected in the area.