I've read in multiple places how most meth in the USA today is Mexican cartel meth. The bans on pseudoephedrine have succeeded in stopping home-brew meth.
Based on my "anecdata" of driving through many of those areas, I would say the problem is much worse than the map shows. Also, it is one of the few maps that showed meth activity by county, in a national context. Recent DEA and CDC reports are all PDFs filled with statistics and not mapped out as well. But, the numbers are only climbing and these areas are still centers of the consumption.
