But - of course - these large grows are illegal.
It's a yearly mission to scour crops by air - and search on the ground - looking for dope. This year's harvest may be bigger than years past.Often times the weed is hidden in the fields of unsuspecting farmers. Farmers -- who, like "Jeff" -- have had enough.
"It's really disappointing that we ended up with marijuana here because we thought we really watched it close," said agriculture consultant "Jeff."
"Jeff" doesn't want you to see his face or use his real name. He says illegal growers have threatened his family with weapons.
"In the middle of the night - I never go to the door without getting a gun," added "Jeff."
He tells me millions of dollars of marijuana has been found on his property.
"This isn't just a few people raising it for recreational marijuana -- this is big money," said "Jeff."
He's working to fight back - hoping to find a chemical that will kill marijuana but not corn. Deputies still plan to look for it hidden among the stalks. Before the law changed -- Franklin County pulled about 20% more plants year-to-year. As for Benton County -- it was about flat. While the agencies can pull the plants --- it's another thing to find the actual criminals.
"It's pretty hard to catch them," said Franklin County Sheriff Richard Lathim.
Gearing up to react to the state's first year of legalized pot. So farmers like Jeff -- can rest at ease.
"It's just like your backyard. You don't want to worry about going into your backyard," said "Jeff."
Franklin County Officials say they expect the majority of plants to be found in cornfields. They attribute much of the activity to dangerous drug cartels from Mexico.