LEBANON, Ore. (AP) — Fourteen people were arrested and 1,400 pounds of pot were seized east of Corvallis in Lebanon in connection with two large illegal marijuana grow operations, authorities said.

The Linn Interagency Narcotics Enforcement team searched two neighboring properties on Aug. 27 and seized the marijuana, more than 9,000 plants, a dozen firearms and more than $6,000, The Albany Democrat-Herald reported.

Sixty-one large greenhouse structures were destroyed on site. Albany Police Department Lt. Juston Alexander said illegal outdoor marijuana grows are much more of a problem in southern Oregon, but over the past few years they’ve been migrating north.

“This is the biggest outdoor grow we’ve dealt with in recent history on private property,” Alexander said.

The 14 people were arrested on marijuana-related charges, as well as criminal conspiracy and illegal firearm possession in one case.

Police say rural property owners are sometimes approached to rent their land with payment in cash for what are presented as legal growing operations. Property owners are urged to question the legitimacy of such offers and contact law enforcement or the Oregon Liquor and Cannabis Commission with questions, police said.