With recreational marijuana legal in 10 states now (and an 11th on the way with Illinois in the process of legalization), tourists may be tempted to bring some dank souvenirs home with them. But can you bring your legally purchased weed with you to the airport? As the Wall Street Journal points out, that all depends.

The laws vary depending on location. In Denver and Las Vegas, where it is legal to possess limited quantities of recreational marijuana, bringing said marijuana to the airport is still illegal. However, possession is legal at airports in Los Angeles, Boston and Seattle. And, of course, it’s important to keep in mind that it’s illegal to transport marijuana across state lines, even if you’re traveling from one state where it’s legal to another.

Enforcing those rules is tricky, however, because as the Wall Street Journal notes, TSA officers can’t arrest anyone. But “in the event a substance that appears illegal is discovered during security screening, our officers will refer the matter to a law enforcement officer, who then follow their own procedures,” TSA spokeswoman Danielle Bennett told the publication.

But despite all the potential confusion, PDX airport spokeswoman Kama Simonds said that generally speaking, it hasn’t been much of an issue for those traveling through Portland.

“Very few recreational users seem to have an issue with the rules as they’ve been set forth,” she said. “Most of the issues we have at the airport are with large, illegal quantities that suggests attempted illegal activity from criminal elements.”

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