No mention of the earlier finds in the Pittsburgh area (south) of early civilization(s) - also about 15,000 years old. The ealier site is an 'outcropping' or something like that. Thought 'unz would like to know about that one too. There was also something found in the McKees Rocks area, if memory serves.
The earlier 'find' in SW Pittsburgh is the Meadowcroft Rockshelter and is believed to be from about 12,900 years ago. The 'dig' at this site has been going on for the last 30 years.