As the United States celebrates Marijuana Day, there are fears it may be the last.
Several states have legalised the drug for medicinal and recreational use, but they could soon be headed for a clash with the Trump administration.
Department of Homeland Security (DHS) secretary John Kelly recently warned of a possible crackdown on legalised pot.
"Its use and possession is against federal law, and until the law is changed by the United States congress, we in DHS along with the rest of the federal government are sworn to oppose all the laws that are on the books."
John Hickenlooper, governor of Colorado, the first state where legal recreational marijuana went on sale in 2014, says Trump's administration shouldn't rush ahead without discussion.
"We should communicate and collaborate and not make a snap decision."
In Colorado, medical and recreational marijuana is now a $1.3 billion industry.
Mr Hickenlooper says shutting it down will drive many to the black market.
"There's just going to be a vacuum to fill and it's all going to be cash and guns. Drug dealers don't care who they sell it to."
While a CBS poll shows over 70% of Americans are against federal action, many pot businesses are preparing for the worst, drawing up contingency plans just in case.