CLE ELUM, Wash. -- Authorities arrested three men Tuesday in connection with a marijuana-growing operation on U.S. Forest Service lands in the Teanaway Valley, about 40 miles northwest of Ellensburg.

The investigation was sparked by a note left at the Cle Elum Ranger Station that described the growing plants and visible plastic water lines, according to a news release from the Kittitas County Sheriff's Office.

Sheriff's deputies and a Washington State Patrol detective discovered more than 12,000 plants in five growing areas, a camp and the three men.

The men -- ages 24, 29 and 38 -- are being held in Kittitas County Jail and each have immigration holds, according to the jail's Web site.

"This is the largest grow and the highest in elevation, over 4,800 feet, that we have seen in Kittitas County," wrote Undersheriff Clayton Myers in the news release. "We were fortunate to get the tip, as this grow was nearly harvested and ready for shipment."