SAN JOSE -- The war on drugs, is no longer concentrated solely along our borders, it's now in our own backyard.

In places such as Santa Clara County where hundreds of marijuana plants were recently discovered tucked away in Joseph Grant County Park near the foothills of East San Jose.

"This isn't some kids planting a few pot plants in the park, this is a big scale production," said Dave Darren, of the Bureau of Narcotics Enforcement.

The State Bureau of Narcotics Enforcement is working with California's Campaign Against Marijuana Planting to search out pot farms in both urban and rural settings and destroy them.

"What you are looking at is what we would call a Mexican national drug trafficking organization large scale marijuana cultivations," Darren said.

The state Attorney General's Office says the Mexican cartels have discovered it's safer and more profitable to grow marijuana in the United States -- in our national forests and on other public land than to risk smuggling the pot across the border.

Last year, CAMP seized almost 467,000 plants with an estimated value of $1.9 billion.

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Video On Demand: Noreen Jaramillo On The Rise Of Pot Farms On Public Lands

"Over the last five years we have really seen this balloon," said Val Jimenez, of the Department of Justice. " What we used to call a big garden of 3,000-5,000 plants is now what we find typical and our large or our big gardens is 25,000 to 50,000 plants."

It is a lucrative business with hired help, often Spanish-speaking laborers, living in makeshift camps beside their crops.

"They are paid to stay up here for the duration and part of their job is to guard and maintain the plants," Jimenez said.

At a hidden field in Santa Clara County, authorities found sleeping blankets, an abundant supply of food and water and pots and pans. Agents said that they saw two Latinos running from the camp, but investigators were unable to find them.

What they did find was 2,000 pot plants valued at $6 million and some weapons and ammunition.

"They are putting the public in danger ," Jimenez said. "Anybody who tries to come up here for some hiking or camping is in serious danger of confronting these people with weapons. That is why it's such a problem and why we take it so seriously."

Hikers are not the only ones in danger.

"There were a couple of instances last year where the suspects in the gardens engaged law enforcement officers who were raiding the garden," Darren said.

Those raids happened last September in Shasta and Butte counties. The shootout resulted in the deaths of four marijuana growers at pot farms near national forest lands. This year, agents made over 40 arrests.

And the problem is not unique to public lands. In the Napa Valley, just minutes away from downtown Napa, a pot plantation was found on private property dotted no trespassing signs. The plants were tucked away, in an area so secluded agents had to be flown in by helicopter and dropped off near the plants. Agents seized 2,700 plants and then tossed them into a shredder. Within seconds an estimated $8 million dollars of marijuana was gone.

Dale Gieringer is the director of NORML -- the national organization for reform of marijuana laws -- claims the federal government has created problem of marijuana growers moving into urban and park areas.

"First of all, they are the ones who drove marijuana on to the public lands when they passed their laws to confiscate people's lands for growing marijuana on it," he said.

Gieringer says he doesn't believe the pot farms popping up in California are the work of Mexican drug cartels, but rather individual growers. Agents disagree saying not only are Mexican cartels responsible, but that they are setting up shop right under our nose here in the Bay Area.

"We had an investigation of one of these large cultivation gardens in Butte County and we found evidence at that site that it was linked to one of our drug trafficking organizations that is based in the San Jose area," Darrin said.

"That was one of the organization that had traditionally been involved in meth manufacturing and distribution. So there is that link between these drug trafficking organizations that are based in Mexico. They have command and control structures here in California."

On Friday, the state will release its latest figures that show that agents seized 25% more pot plants this year than last year. And with millions of acres of public land in California and fewer agents to investigate due to budget cuts, the business is sure to grow.