At the 1998 Olympics in Nagano, Japan, officials stripped the Canadian snowboarder Ross Rebagliati of his gold medal after he tested positive for THC. Rebagliati contested the ruling. He said he had quit smoking pot to train for the games, but had inhaled secondhand smoke at snowboarder parties.

The appeal worked. After 36 hours Rebagliati’s medal was restored. He flew to California and in an appearance on the Tonight Show with Jay Leno acknowledged past marijuana use. The next time he tried to enter the US, Rebagliati learned he was barred from the country for life, according to his immigration lawyer Leonard Saunders.

More than 20 years later, travelers who use cannabis still face significant barriers.

America’s lifetime ban on foreign cannabis users remains in force, even though the majority of US states allow medical use and Canada has fully legalized. Though the law is only sporadically enforced, it’s a serious headache for those affected. At least 40% of Canadians have tried marijuana. The prime minister, Justin Trudeau, smoked up while serving as a member of parliament.

With hostility to immigrants Donald Trump’s signature issue, it seems unlikely that the law will change anytime soon. Weeks before Canada legalized last October, US Customs and Border Protection said it reserved the right to turn back Canadians working in the cannabis industry.

Fortunately for Canadians, and other foreign nationals, relatively few visitors get asked about their drug history at customs. And those who are barred can obtain a waiver to re-enter the country, but it generally requires hiring an immigration lawyer. “The only one who benefits from this process is me,” Saunders said. For travelers who have tried cannabis and get asked the question, he recommends not answering and turning back as the best option.

Airports in some legal cities have set up amnesty boxes where travelers can surrender their stash. Illustration: George Wylesol/The Guardian

Travel with cannabis within the US, meanwhile, has gotten easier.

The Transportation Security Administration (TSA) which staffs airport security checkpoints in the US, is a federal agency, but it is not tasked with arresting passengers carrying small amounts of marijuana. When agents find some on a passenger, they’re likely to turn the person over to local law enforcement, who tend not to arrest people for cannabis use in legal states.

Airports in some legal cities have set up amnesty boxes where travelers can surrender their stash without risking prosecution. But intentionally or not, some travelers forget to throw away their weed.

It’s fair to assume this because factory-made edibles are the best thing to happen to air travel since the individual screen, and possibly the jet engine. Nowhere is the cliche of cannabis “taking the edge off” more right than on a flight. In flat-bed first class, it’s like a return to the womb. (The same cautions about edibles apply. There has been at least one ugly, and perhaps even hazardous, incident in the air involving a passenger who over-consumed.) And while marijuana used to look like plant matter and could fill a room with its smell, it now comes in the form of chocolates, gummy bears, and vape pens, all of which are hard to distinguish from legal products.

My home airport has dropped the pretense of enforcing marijuana laws. Instead it has adopted an aptly named “LAX Marijuana Policy”: travelers can carry small amounts for personal consumption. They negotiate the security checkpoints at their own risk, and of course have to comply with local laws wherever they land.

Ross Rebagliati would probably approve. Today the snowboarder uses cannabis openly and has a started a brand called Legacy. It’s not currently available in the US.