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 a.m. 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.
The store has hired a private security firm to help with traffic and parking issues that might arise.
Hackett said she has 50 lbs (23 kg) of product on hand, and to avoid a supply shortage the shop will limit purchases to quarter-ounces on Wednesday, including joints, raw buds or cannabis-infused edibles such as pastries or candies.
A quarter-ounce sampler packet with seven strains of weed labeled with names such as "King Tut Kush" and "Gypsy Girl" - each said to produce a different kind of high - will retail for $85 to $90, including tax, Hackett said.
TURNING POINT IN DRUG CULTURE
Like other stores, Botana Care will also stock related wares, including pipes, rolling papers, bongs, and reusable, locking child-proof pouches.
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.
Nearly 20 states, including Colorado and Washington, had already put themselves at odds with the U.S. government by approving marijuana for medical purposes.
Opponents warned that legalizing recreational use could help create an industry intent on attracting underage users and getting more people dependent on the drug.
Comparing the nascent pot market to the alcohol industry, former U.S. Representative Patrick Kennedy, co-founder of Project Smart Approaches to Marijuana, said his group aims to curtail marijuana advertising and to help push local bans on the drug while the industry is still modest in stature.
"This is a battle that if we catch it early enough we can prevent some of the most egregious adverse impacts that have happened as a result of the commercialized market that promotes alcohol use to young people," he said.
Under Colorado law, however, state residents can buy as much as an ounce (28 grams) of marijuana at a time, while out-of-state visitors are restricted to quarter-ounce purchases.
Restraint was certainly the message being propagated on New Year's Eve by Colorado authorities, who posted signs at Denver International Airport and elsewhere around the capital warning that pot shops can only operate during approved hours, and that open, public consumption of marijuana remains illegal.