GUADALAJARA — The methamphetamine laboratories that once plagued California’s hinterlands and powered a national explosion of drug abuse have been replaced by an increasing supply from Mexico, U.S. law enforcement officials say.

Methamphetamine production has surged south of the border, from Baja California ranches to the highlands of Michoacan to the industrial parks here in Mexico’s second largest city, where authorities in January busted the largest laboratory ever discovered in the Americas.

The fortress-like compound ringed by high brick walls housed 11 custom-designed pressure cookers that could produce 400 pounds of the drug per day. It dwarfed anything ever found in California, where the standard cooking tool is a 23-quart beaker and a 20-pound batch is considered a good production day.

Drug traffickers, some of them ex-convicts and fugitives from the United States, including a former chemistry professor from Idaho arrested last month, authorities say, have resettled in Mexico because of the easy access to pseudoephedrine and other chemicals.

Authorities now estimate that 80% of the methamphetamine on U.S. streets is controlled by Mexican drug traffickers, with most of the supply smuggled in from Mexico. Methamphetamine seizures at the U.S.-Mexico border jumped 50% from 2003 through 2005, from 4,030 to 6,063 pounds.

Meanwhile, the merry-go-round of users, losers, small-time dealers is the only portion of the cycle that populates US jails. Or Mexican jails.