Bueng Kan governor Nirat Pongsitthavorn and Bueng Kan police chief Maj Gen Thiwa Boondamnern said 608 bars of marijuana had been seized with each weighing 1kg.
Police also seized a pickup truck, six motorcycles and two trolleys from the scene.
Acting on tip-offs, police said they staked out a public pond in Ban Had Hae in Tambon Khok Kwang on Tuesday night.
Police said they spotted men carrying 14 bags onto the pickup truck but they managed to escape.