ROGUE RIVER, Ore. » Police in the southern Oregon community of Rogue River say a man walking through a park discovered a portable toilet filled with marijuana plants.

The agency posted a photo on social media Wednesday, saying it’s the largest seizure of pot the department has ever made.

Marijuana grows are common in southern Oregon, which has some of the nation’s best conditions for outdoor cultivation.

Chief Ken Lewis said Thursday police still don’t know how the pot got there. He said it could be anything from a pick up point to a disgruntled citizen making a statement about all the marijuana grows.

Lewis said a public works employee checked the toilet three hours before the discovery was made and it was empty. People playing tennis on a nearby court saw nothing suspicious.