The smell of chemical solvents was overwhelming at the remote mountaintop site in the northern state of Sinaloa, where Navy personnel on patrol last week stumbled across an enormous holding tank they initially thought might be used to water a marijuana plantation.
Instead, the tank fed water to a pair of enormous sheds where sailors found 13,000 gallon) of ephedrine, a chemical used to make methamphetamine. That is enough to produce 40.2 metric tons of the drug, or about 309 million individual doses.
The members of the Navy patrol found drums, barrels and other chemicals used in the process at the site, located on a dirt road miles from the nearest town.
"This is one of the heaviest blows to the drug traffickers in this administration ... as far as synthetic drugs are concerned," said Vice Admiral Jorge Humberto Maldonado, who estimated that the precursors were enough to produce methamphetamine worth $1.4 billion in street value.
That would make it larger than the May seizure of more than 8 tons of finished methamphetamine at a clandestine drug lab in the western state of Michoacan.
In 2006, Mexican officials seized more than 19 tons of a similar precursor chemical, pseudoephedrine acetate, at a Pacific coast port. Mexico subsequently banned almost all legal uses of pseudoephedrine, but traffickers have apparently found other illegal routes to get the material. On Tuesday, Guatemalan authorities confiscated nearly 10 million pseudoephedrine pills worth $33 million, the country's biggest seizure of the substance.
The Navy carried out the Thursday bust in Mexico's so-called Golden Triangle, where traffickers long have operated. But was no immediate indication which drug cartel ran the facility.
The Navy also reported Tuesday that it had detected a shipment of cocaine hidden inside the carcasses of frozen sharks aboard a freight ship at the Gulf coast port of Progreso. The Navy did not provide an immediate estimate of the amount of cocaine found, but said it had been detected in an X-ray inspection of the shipment.
Also Tuesday, police found the bodies of seven young men who were beaten or shot to death in the state of Durango in northern Mexico.
At least three of the bodies had bullet wounds. The others appear to have been beaten to death.
Investigations into the case are continuing, but the style of the killings suggested the involvement of drug gangs.
An employee of the state prosecutor's office, who was not authorized to be quoted by name, said the bodies were found on a street in the city of Gomez Palacio.
And in the western state of Michoacan, three suspected kidnappers were killed in a shootout with local police in the city of Uruapan. State prosecutors said the shootout occurred Tuesday after police got a report of kidnappers fleeing in a truck and attempted to stop them.
More than 10,800 people have been killed by drug violence since President Felipe Calderon launched a nationwide crackdown on organized crime in late 2006.