Thanks for the info. It's rather interesting they've been around for so long. The general view on the Mexican cartels is that these are criminal organizations that can grow immensely wealthy and powerful in a short time, but they mostly don't have a lot of longevity. They often don't stay on top for a really long time and disintegration is common. While the Gulf Cartel has certainly suffered from setbacks - most infamously of course being directly challenged by a group they spawned themselves, the Zetas - it also seems to keep on rebuilding itself. This considered they actually pique my interest more than the Sinaloa Cartel.

The groups in the northeast of the country also seem to be exceptionally violent compared to those in western Mexico. This may just be an idea of course.