A team of officers conducted a warrant at Clifton caravan site at 9.15am on Thursday 2 June 2011.
A quantity of cannabis and cash was seized during the operation.
A man and woman, both aged 40, were arrested at the scene on suspicion of possession of class B substance, possession with intent to supply a class B substance and money laundering.
They remain in police custody for questioning.
Inspector Jo Brooksbank, of the York Rural Safer Neighbourhood Team, said: “Drugs-related crime is a blight on society and must be tackled at every opportunity. North Yorkshire Police and our partner agencies will not hesitate to take action to disrupt this illegal activity and bring offenders before the courts.
“I urge anyone with information about suspected drug dealing or other drugs-related offences to come forward to the police as soon as possible. If people are frightened or unsure about contacting the police directly, then an anonymous call to the independent charity Crimestoppers is the best alternative.”
Insp Brooksbank thanked the York Compass Drugs Intervention Programme team who provided additional support and professional guidance in the custody area in relation to the operation.
Anyone with information that could assist this investigation or other drugs-related offences are urged to contact North Yorkshire Police on 0845 60 60 24 7, quoting the reference number 12110089910.
Alternatively, contact Crimestoppers anonymously on 0800 555 111.