This is how it works in my state (Louisiana)- a game warden can do what no police officer can do. He can actually come into your house and search it, without a search warrant of any kind. He can stop your car on the highway, search it, and does not have to have a reason for doing so, other then he thought you looked suspicious. They have more power then any other law enforcement agency.
He can come on your land, in your house, inside your vehicle.He can do anything he wishes to do. It is possible he may have that power in CA. also. And evidently they do.
Edit- to those that would thumb down a correct answer, this was taken off a link concerning this very subject-
"Search with or without Warrant
The laws in many U.S. states allow game wardens to conduct certain types of searches with or without search warrants. The law in Louisiana for instance states in part "...any commissioned wildlife agent may visit, inspect, and examine, with or without [a] search warrant, records, any cold storage plant, warehouse, boat, store, car, conveyance, automobile or other vehicle, airplane or other aircraft, basket or other receptacle, or any place of deposit for wild birds, wild quadrupeds, fish or other aquatic life or any parts thereof whenever there is probable cause to believe that a violation has occurred. Commissioned wildlife agents are authorized to visit or inspect at frequent intervals without the need of search warrants, records, cold storage plants, bait stands, warehouses, public restaurants, public and private markets, stores, and places where wild birds, game quadrupeds, fish, or other aquatic life or any parts therof may be kept and offered for sale, for the purpose of ascertaining whether any laws or regulations under the jurisdiction of the department have been violated...." The laws in other states may grant more or less search and seizure authority. These exceptions granted to game wardens are still considered to fall within the constitutional limits of search and seizure as outlined in the U.S. Constitution."
@ walter- two years ago, the wardens paid a vist to a friend of mines house, unannounced and without a warrant- they made a visual inspection of each room, and his freezer. They then confiscated two of his deer mounts. This was based on a complaint that someone had made stating he had killed over the legal limit of deer the year before. I have to add, he was found guilty of the charge.