The advice given in the above post will protect you legally for traveling in ALL States. In a nutshell, the firearm must be unloaded and in a case--preferably locked--in a part of the vehicle not easily accessible to the driver while the car is in motion. Ammunition must be stored separately. To keep it even more legal, I would not store the ammunition in loaded magazines, but by itself, preferably in boxes that are packed in their own separate case.
Hiding in plain sight...