COLUMBIA - From the ground, the pine forests near the North Carolina line appear unremarkable - rows of trees that eventually will be chopped down to make way for a housing development.
But hidden among the trees, visible only from the air, police in recent weeks have found a bumper crop of what some experts consider South Carolina's most lucrative harvest: marijuana.
More than 30,000 marijuana plants have been seized in two July busts just south of Charlotte, N.C., bringing the total amount of pot seized this year to 38,000 plants. That's nearly three times the number confiscated across South Carolina in all of 2005, and nearly as many as were seized statewide last year.
State and federal authorities, and experts in marijuana policies, say that what appears to be a bumper crop of the illicit plants this year is linked to two factors: bolder and more sophisticated marijuana growers producing more of the drug, and law enforcement getting better at finding the growing operations.
"The traffickers are doing just larger amounts of grows, and larger crops, in places where law enforcement is doing a better job in finding them," said John Ozaluk, the federal Drug Enforcement Agency's top agent in South Carolina. "It's a very bold thing to do, to plant that many marijuana plants."
Much of the marijuana that ends up in South Carolina is grown in Mexico, according to federal officials. But transporting drugs across the U.S.-Mexican border means high costs and security risks, something Mr. Ozaluk said has led to more homegrown marijuana.
Growers have plenty of financial incentive to get into the booming domestic industry. A 2006 study by Virginia-based researcher Jon Gettman said marijuana was the nation's largest cash crop, at $35.8 billion over a three-year period, and was the single largest cash crop in 12 states, including South Carolina. From 2003 to 2005, marijuana production and sales amounted to a $142 million industry in the state, ahead of tobacco ($97 million) and cotton ($92 million).