I'm not sure how common black tar heroin is anymore. The Mexicans have been producing their own high grade heroin for at least the last 15 years now. And the northeast is the last region where the Mexicans are not the dominant traffickers. They already are in the south east. But in the northeast you still have competition from Colombians, Dominicans, Cubans, Asians, the LCN, etc.
tar for the most part is the most prevelent form of heroin in almost all areas outside of the northeast and chicago/detroit to a lesser extent. particularly southern california and the entire southwest, even to a lesser extent in southern cities like atlanta.
