DENVER — At the Native Roots Apothecary, a discreet marijuana shop in a grand old building in Denver’s busy 16th street shopping mall, business is so brisk that customers are given a number before taking a seat to wait their turn.

There are young men in ball caps, nervous-looking professionals in suits, and the frail and elderly. Staff say customers have been flocking to their outlets since Colorado voted to allow recreational pot use for adults from January.

Six months on, Colorado’s marijuana shops are mushrooming, with support from local consumers, weed tourists and federal government taking a wait-and-see attitude.

Tax dollars are pouring in, crime is down in Denver, and few of the early concerns about social breakdown have materialized – at least so far.

‘The sky hasn’t fallen, but we’re a long way from knowing the unintended consequences,” said Andrew Freeman, director of marijuana coordination for Colorado. ‘This is a huge social and economic question.”

Denver, dubbed the ‘Mile High” city, now has about 340 recreational and medicinal pot shops. They tout the relaxing, powerful or introspective attributes of the crystal-encased buds with names like Jilly Bean, Sour Diesel and Silverback Kush.

In the first four months, marijuana sales amounted to more than $202 […]