The illicit farm - located on the 2500 block of McCallister Street in Riverside - reportedly emitted a strong odor that prompted an anonymous source to contact authorities, Riverside Police Department Officer Ryan Railsback explained to KTLA. 

The property sits approximately nine miles outside of Riverside and roughly eight miles outside of Corona. It is surrounded by trees and a few sprinkling of houses and is five minutes away from the Riverside Freeway.

Detectives were granted a search warrant, which gave them access to the property on Thursday. The size of the property meant the search extended well into Friday. 

The illicit farm - located on the 2500 block of McCallister Street in Riverside - emitted a strong odor which prompted an anonymous source to contact local authorities

The massive property is believed to have formally been a plant nursery and investigators discovered that the product was being housed in multiple greenhouses. 

The cannabis plants were also in various stages of maturity. It took investigators all day to collect the plants, using forklifts to load them onto trucks. 

Railsback shared that authorities also 'found the chemicals used' for growing the plants. 

'Thousand of gallons of pesticide and thousands of pounds of the fertilizer used for this cultivation process,' he added.

Investigators found roughly 40,000 pot plants at various stages of maturity and valued at $20million

The site is believed to have formally been a plant nursery and investigators discovered that the plants were housed in multiple greenhouses on the massive property

The officer also shared that animal control was called to the scene to collect dogs that were found on the premises. 

According to Railsback, no one was at the scene at the time that the warrant was served. Police did find makeshift living quarters, however. 

Authorities are looking into who owns the part farm, Railsback shared. 

At the scene, police also a variety of equipment, including: multiple cars, a tractor and a forklift. Railsback indicated that the items would be permanently seized through asset and forfeiture. 

California does allow for recreational marijuana usage. 'It is very illegal in the city of Riverside to have anything more than six plants for your personal use, ' Railsback added. 'And it's obvious that this was a full-scale operation going on that was conducted illegally.'

The property sits approximately nine miles outside of Riverside and roughly eight miles outside of Corona. It is surrounded mostly by trees and a few sprinkling of houses and an approximate five minutes away from the Riverside Freeway

No one was at the scene at the time that the warrant was served. Police did find makeshift living quarters at the scene, however

At the scene, police also a variety of equipment including: multiple cars, a tractor and a forklift. Those items will be eventually seized by the Riverside Police Department