By the mid 1990s they had close connections with Colombian traffickers like Fabio Ochoa Vásquez of the Medellin cartel and by the early 2000s they were working with synthetic drugs provided by Zhenli Ye Gon.
[8] The cartel operated in at least six Mexican states: Michoacán, Colima, Jalisco, Mexico City, Nuevo León and Tamaulipas, where it produced marijuana and heroin.
On October 28, 2009, Oscar Nava Valencia (El Lobo) was captured after a gun battle with Mexican Army troops in the municipality of Tlajomulco de Zuniga, Jalisco.
The Milenio broke into smaller factions, most notably La Resistencia, headed by Ramiro Pozos El Molca, and the Jalisco New Generation Cartel (CJNG), headed by Nemesio Oseguera El Mencho, and started a turf war for the control of the region.
On January 29, 2011, Oscar Nava Valencia was extradited to the United States to face charges of conspiracy and drug trafficking in the Southern District of Texas.