Proprietors of the first marijuana retailers licensed to sell pot for recreational use in Colorado were busy rolling joints and stocking up their leafy merchandise ahead of a grand opening on Wednesday that marks a new chapter in America's drug culture.

Thirteen former medical marijuana dispensaries newly cleared by state regulators to sell pot to consumers who are interested in nothing more than its mind- and mood-altering properties were slated to begin welcoming customers as early as 8 am local time.

When they do, they will be launching an unprecedented commercial cannabis market that Colorado officials expect will ultimately gross $578 million in annual revenues, including $67 million in tax receipts for the state.

Possession, cultivation and private personal consumption of marijuana by adults for the sake of just getting high has already been legal in Colorado for more than a year under a state constitutional amendment approved by voters.

But starting New Year's Day, cannabis will be legally produced, sold to the general public and taxed in a system modeled after a regime many states have in place for alcohol sales - but which exists for marijuana nowhere in the world outside of Colorado.

Due to the novelty factor, operators of the first group of retailers slated to open their doors in the Denver area and a handful of other locations were anticipating a surge in demand for store-bought weed.

Inside a warehouse tucked away in the blue-collar Denver suburb of Northglenn, a trio of workers were feverishly rolling hundreds of marijuana cigarettes by hand in preparation for the onslaught.

"We expect to have 2,000 joints ready to go by the time we open," said Robin Hackett, 51, co-owner of Botana Care, who said she expects between 800 to 1,000 customers to patronize her store the first day.

Voters in Washington state voted to legalize marijuana at the same time Colorado did, in November 2012, but Washington is not slated to open its first retail establishments until later in 2014.

Still, supporters and detractors alike see the two Western states as embarking on an experiment that could mark the beginning of the end for marijuana prohibition at the national level.

"By legalizing marijuana, Colorado has stopped the needless and racially biased enforcement of marijuana prohibition laws," said Ezekiel Edwards, director of the American Civil Liberties Union's Criminal Law Reform Project.

Cannabis remains classified as an illegal narcotic under federal law, though the Obama administration has said it will give individual states leeway to carry out their own recreational-use statutes.

Reuters