If you're planning a trip to the United States, be very careful. You could easily break one of our laws and not know it.

We're not talking about obvious illegal behavior, like throwing a chair through your hotel window. No, there are other, more obscure offenses that could get you in trouble.

Say you visit Alabama. Whatever you do, do not sprinkle salt on any railroad tracks. Not only is it against the law in that southern state - it's punishable by death.

illistir, Flickr Creative Commons
This may be the proverbial 'better mousetrap,' but you'd best hope you don't catch anything in it in California.

Really, at least according to warnings that are flying all over the Internet. We can't find the actual legal citation, though, and this is quite possibly one of those urban legends.

Want to go whale hunting? Don't do it in Utah, where it's supposedly illegal. Doesn't matter that Utah is 1,500 kilometers from the nearest ocean. Whale hunting is forbidden.

And be warned, you can't legally set a mousetrap in California without a hunting license, either. Tease a skunk in Minnesota, and they can haul you off to jail.

mikebaird, Flickr Creative Commons
Going after one of these? It had better not be in Utah.

You're probably saying, "If these silly old laws are real, why not get rid of them?" Well, suppose you're on the town council in Waterville, Maine. You stand up and proclaim that it's high time to do away with the law that makes it illegal to blow your nose in public. The voters in Waterville would toss you out of office for wasting time on such things.

And a lot of old laws, if they really exist, have to do with sex, religious beliefs, and cuddly animals. So some interest group would get involved if you made a fuss. So laws like one in Indiana that makes it illegal for monkeys to smoke stay on the books.

As for that salt-on-the-tracks law, we asked around to see why such a thing might have become law. Turns out that in the heyday of railroading all over the nation, crews used to spread salt in the wintertime. Freezing mud that reached track level could derail a train, and rock salt kept the mud soft. Problem was, the salt attracted cattle. And hitting one of them could derail a train for sure.