POLK COUNTY -- Brian Finn periodically cuts firewood from the perimeter of a five-acre stand of trees that's almost like an island on his grass field at the north end of Polk County.
But he hadn't walked through that lot for several years until Sept. 24. On that day, Finn's visiting daughter and her new husband asked to scout the parcel of tall cherry and oak to find a backdrop for wedding pictures.
"I asked if they found what they were looking for ... they told me there were the most beautiful flowers in there," Finn said, noting that they then presented him with a marijuana leaf.
Stunned, Finn trekked through the thick underbrush into a man-made clearing, more than an acre wide, to find 3,000 marijuana plants in neat rows.
"I cut wood out there without ever going in ... I never would have seen it," Finn said as he stepped over hundreds of feet of irrigation hoses, drip lines and the occasional empty beer can. Authorities had uprooted the marijuana garden a few days earlier.
Finn said there's a part of him that enjoys having a funny story to tell.
Still, "I find it offensive they violated my personal property," he said. "They don't have any right."
Discoveries of large-scale marijuana gardens have become common on remote stretches of federal land in Southern and Eastern Oregon during the last several years.
Even as more have cropped up in the Northwest corner of the state, Polk County had remained mostly free from clandestine plantations.
Mike Holsapple, a Polk County Sheriff's sergeant and member of the Polk Interagency Narcotics Team (POINT), said the fact that much of this county's secluded land is gated by timber companies and state agencies has probably delayed large marijuana grow operations here.
Until this summer, Holsapple continued. Law enforcement agencies discovered 3,700 marijuana plants off a logging road southeast of Grand Ronde in July.
And last week, they hit two more gardens: the one on Finn's farm and another with almost 2,000 plants in a secluded acre of Department of Forestry land on Green Mountain near the Polk-Benton county line.
"It's nothing new for the state," Holsapple said. "But it's new for us."
The outdoor grows that the sheriff's office and local drug teams have been accustomed to finding in the past 10 years have consisted of 20 to 80 plants per site, and maybe 200 or 300 plants seized annually.
Almost 9,000 plants have now been confiscated during seven seizures in 2010. No arrests have been made in conjunction with the three large plantations, which were unoccupied at the time of the raids. The street value of the buds was approximately $1.2 million.
The findings have occurred as local demand for the drug has risen sharply, Holsapple said.
"We have suppliers who were selling eighths and quarter ounces and are now selling pounds," he said.
The outdoor marijuana grow season starts in April and ends whenever the rain or cold weather sets in; that coincides with eradication programs run by regional and state police teams.
"We haven't seen the numbers yet for 2010," said Sgt. Erik Fisher of Oregon State Police's Drug Enforcement Section. "But it's been a busy year."
Because remote areas in the Cascade and Coast Ranges entail taller vegetation and more rugged terrain, Northwestern Oregon doesn't see vast plant seizures that eastern and southern counties in the state do, Fisher said.
"But we're finding more in the valley than we have historically," he said.
He then added: "Or are there an increased number of grows or are we just getting better at finding them?"
Many large grows are believed to be long-distance operations perpetrated by Mexican drug cartels. Fisher said it's hasty to attribute grows that way until suspects are arrested and evidence found.
Still, OSP has nabbed gardeners with ties to such organizations. At the Green Mountain site, officials found gardening and watering equipment, a .22 caliber rifle, fresh food, gardening supplies and a camp -- all of which have been signatures of cartel grows.
"We suspect that's what this is," Holsapple said. "We've expected that would happen, to where eventually they would migrate to our area."
Finding armed gardeners and booby traps at marijuana grows has become prevalent enough in Oregon that the state Department of Justice specifically notes them in resource guides focusing on criminal risks in forestland.
"They can be dangerous," Holsapple said.
Deputies had been aware of the south county site for about a month before the Sept. 24 raid, the timing for which coincided with hunting season, Holsapple said.
"The woods are opening up, hunters are going to be out there and we don't want them running into these guys and having a confrontation," he said. "That's why we're trying to get this stuff out of the ground."
Authorities learned of the grow on Finn's property as they were leaving Green Mountain. Holsapple said he's seen instances of marijuana grown under the cover of crops, but never in this setup.
Last week, Finn picked half-full bags of fertilizer, empty bottles of ammonium nitrate, tools, cans of food and other items left behind by the illegal gardeners.
They had run aluminum irrigation lines under the brush to a nearby water pipe to quench their crop, and felled small trees against still-standing ones just inside the perimeter to obscure the view from the outside, Finn said.
The garden had probably been here since the spring, he guessed. Because it sits hundreds of yards to the back of his home, he's never noticed people going to or from it, he said.
But "I'm going to be cruising it a lot more closely now," he said. "All I can say is if anybody has land like this, check it."