Long before marijuana makes it to urban areas where pushers sell it to anyone with a buck and a habit, the weed is grown in country fields.

Police in rural counties make it their mission to rid the countryside of the weed before it's bought and sold on city streets.

And sometimes they risk their lives to do it.

"We're always trying to catch the people who are responsible for growing pot," said Bollinger County Sheriff Dan Mesey, whose department confiscates hundreds of marijuana plants each year in a county where isolated fields are tempting an increasing number of pot growers.

Because marijuana crops represent hundreds and sometimes thousands of dollars to growers, the crops are often fiercely guarded, representing a real threat to law enforcement officials on search-and-destroy missions.

"You never know what's in the woods with you," Mesey said.

"People use booby traps, guard them with guns. A full-grown marijuana plant can have a street value of $1,000. People are willing to hurt policemen for $1,000 a plant, especially when they've got 30, 40 or 100 of them they're trying to protect."

Mesey, other area sheriffs and the Missouri Highway Patrol have found it increasingly difficult to track down people who grow marijuana, one of the most common street drugs available, mostly because growers are becoming more creative in ways they hide the illegal weed from police.

Although more than 24 million marijuana plants have been confiscated in Missouri this year alone, there are millions more out there.

"Like all criminals, growers try to find ways to circumvent the law and circumvent investigators," said Cape Girardeau County Sheriff Norman Copeland.

"A lot of it is sold around here, and the supply will not keep up with the demand."

Marijuana eradication efforts in the state are particularly heavy this time of year, known as the harvest season to pot growers and police.

A federally-funded program headed up by the Missouri Highway Patrol uses helicopters to spot marijuana crops. A trained eye can spot the plants from the air because of their distinctive color. This method is especially useful in rural areas, said Lt. Jim Watson with the patrol.

Watson said this year the eradication efforts have been particularly successful. Last year the patrol confiscated more than 12 million marijuana plants, and the figure has doubled this year.

The program has also yielded 721 pounds of processed marijuana so far this year, Watson said.

"A lot of it is a result of officers who follow up on leads and because of our hotline," Watson said. "We've received 174 reports on that telephone line since the (growing) season started, and it's the harvest season right now. So we're pretty active."

The hotline, 1-800-BAD-WEED, takes anonymous tips from people throughout the state who spot marijuana plants and want them confiscated. Watson said law enforcement agencies often rely on such tips to help in eradication efforts.

Mesey said anonymous tips from residents prove to be one of the best ways his department finds marijuana crops in his county.

"We rely on information from the public, and we've got to have it," Mesey said.

"People need to give us that information because it's their families who are affected by drugs. It's their kids. It's the mom-and-pop stores that are affected when some guy sticks a gun in their face and robs them to get money to buy more dope."

Copeland said marijuana growers are becoming more sophisticated in the ways they hide the plants. Just this week in Bollinger County a man was charged with manufacturing marijuana after police acting on an anonymous tip found five buckets, each with a marijuana plant growing in it, in woods behind his house.

The buckets allowed the man to move the plants around another way to keep from being spotted.

Copeland said in the past year one grower apprehended by police was grafting leaves of another plant onto marijuana plants in an effort to hide the distinctive color of marijuana leaves.

And more and more marijuana growers are setting up indoor growing facilities, probably the most difficult for police to detect, Copeland said.

Scott County Sheriff Bill Ferrell said that in parts of Scott County it is extremely hard to spot marijuana because of heavy foliage.

"And more people in the past couple of years have started growing it in their attics and basements." the sheriff said.

"Even when it's outdoors, the only way you can prove who's responsible for growing it is if you see them cultivate it, watering it or caring for it."

Ferrell agreed that the best way for police to catch pot growers is through tips from citizens who see suspicious activity or run across a patch of the weed.

Watson of the Highway Patrol said in the five years since the marijuana eradication program has been active, its efforts have made a significant dent in marijuana production in the state. In fact, in 1989, Missouri led the nation in the amount of cultivated marijuana plants seized. More than $1.6 billion worth of the illegal weed was destroyed that year.

Mesey said the helicopter searches have discouraged some growers but have led others to come up with high-tech ways to hide the plants from law enforcement officials.

"In our county the growers have noticed we are watching them from the skies," he said.

The result has been a smaller amount of marijuana hitting the streets.

"That's proven by the price of marijuana now on the streets," Mesey said. "It's gone up to anywhere from $55 to $65 for a quarter of an ounce. When I first got into law enforcement (27 years ago), $45 bought an ounce.

"It goes right back to basic economics: supply and demand."

Ferrell said rural sheriff's departments should ideally have separate units that handle drug seizures and arrests.

"With the drug problem, you almost need to be there before it happens to make a case," Ferrell said.

Mesey said rural law enforcement agencies are crucial in the fight against drug use.

"It's always bewildered me that when they talk about the war on drugs they send 90 percent of the money into urban areas," Mesey said. "We're the ones with the smaller police and sheriff's departments, and we're out here fighting it in the woods where they're making it."