Evidently, they’re along Interstate 44:
Oklahoma, ranked eighth highest in 2004, has now risen to sixth, despite a modest decline in the number of methamphetamine “incidents” recorded. The biggest drop seems to be along the Left Coast, for reasons I’m not entirely sure of. (Oregon, it appears, now requires prescriptions for all products containing pseudoephedrine, though the effect of this law is yet unclear.)
Still, Missouri remains your go-to state for illegally produced meth. I assume they’re not crazy about that distinction.