Firearm laws can vary greatly from state to state, and ignorance isn’t a valid legal defense, so it’s important for responsible gun owners traveling with a gun to be aware of the regulations governing firearm usage for every state along the way. Traveler’s Guide To The Firearm Laws Of The Fifty States, now in its 20th edition and updated for 2016, is a quick reference guide that covers everything from transporting a firearm in a vehicle to concealed carry reciprocity to where and how a gun can be carried for all 50 states and the District of Columbia. Written and researched by J. Scott Kappas, the 2016 Traveler’s Guide also includes a handy introduction that defines many terms of importance to anyone traveling with or carrying a firearm outside of their home state. Price: $15. Contact: Traveler’s Guide (859) 491-6400; gunlawguide.com.