Ok as we all (or anyone who knows anything about the diesel biz) Colombia is the worlds leading producer of quality no. 4 heroin since the Golden Triangle's market share/production has been shrinking since the late 80's early 90's. Mexico'

My question is this, how much, and how common is it for Colombian heroin to transit Mexico on its way to the US? For the past 20 years or so most of their coke (according to govt. sources) comes in via the Mexican border, but for some reason this is not the same case for diesel (east coast word for dope) which still sees a lot of direct importation from Colombia to the eastern US. I have figured 3 reasons why this may be so.

1. Mexican groups have their own dope (usually black tar, sometimes brown powder, though that is often just tar crudely smashed into a powder w/ a cutting agent) so they miight not want to, or let anyone, move Colombian no. 4 through Mexico.

2. Heroin is active in smaller amounts, so it is more feasible to smuggle it direct to the US via such methods as couriers swallowing loads of it.

3. Similar to 1, Meixcan border would lead it into the Western US where Black Tar is dominant. I doubt Mexicans want people switching to the more costly (esp for them) No. 4 powder. Even though tar has gotten MUCH better in recent years, to the point where many junkies now prefer it, the fact it is TAR makes it so much harder on a users system then powder.

Anyway, anyone have any more information/reading on this subject? Thanks in advance amigos.