Will, this came up in my CCW class with the LEO trainer. His suggestion, to make sure you are 100% compliant, is to call the state police or the states attorney general of every state you are going to pass through, tell them your situation, and get them to tell you what's safe. Also, call far enough ahead of leaving for your trip that when you talk to these officials, ask them to send or fax their business card with a copy of the law that they are quoting to you. This way, you know you are getting 100% accurate, up-to-date information and you have an official to refer an LEO to should he question your method of carry in ANY state! It takes a little preparation and 4 or 5 phone calls, but it's almost 100% fool-proof and can seriously limit your liability if your pulled over in the middle of your weekend.
