Nevada has become the fifth state in the US selling marijuana for recreational purposes, opening a market that is expected to outpace any other in the nation thanks to the millions of tourists who flock to Las Vegas.

People began purchasing marijuana in the state shortly after midnight on Saturday. Voters approved legalization in November, making Nevada’s the fastest turnaround from the ballot box to retail sales in the US.

The state joins Colorado, Oregon, Washington and Alaska in allowing adults to buy a drug that is still banned by the federal government.

More than 100 people were in line at the Source dispensary, at a Las Vegas-area strip mall on Saturday morning. Kristin Deneal said she got in line at 5.45am, after a store that opened at midnight closed before she could make a purchase. She brought a folding chair and sat by the door, striking conversations with the security guard and others as the line continued to grow before doors opened at 9am.

Deneal, a Las Vegas resident, said she was happy to be able to legally buy a drug that for decades she has had to buy through acquaintances. She said smoking marijuana helped her cope with health conditions while working a stressful job at a bank.

“It looks like they have enough stuff for everyone, it’s just a question of getting through the door,” she said.

State senator Tick Segerblom, one of the main proponents of marijuana legalization in Nevada, made the first purchase. Deneal and others followed.

On the Las Vegas Strip, hundreds of people lined up at Essence Cannabis Dispensary. People were excited and well-behaved as a lone security guard looked on. A valet was available to park the cars of customers. A cheer erupted when the doors opened.

Those 21 and older with a valid ID can buy up to 1oz of pot. Tourists are expected to make nearly two of every three recreational purchases in Nevada, but people can only use the drug in a private home.

It remains illegal to light up in public areas, including the Las Vegas Strip, casinos, bars, restaurants, parks, convention centers and concert halls – places frequently visited by tourists. Violators face a $600 fine. Driving under the influence of marijuana is still illegal.

Despite the limits on where people can get high and restrictions on where the industry can advertise, dispensaries worked furiously to prepare for the launch. They stamped labels on pot products, stocked up their shelves, added security and checkout stations, and announced specials.

Desert Grown Farms hired about 60 additional employees. Workers in scrubs, hair nets and surgical masks slapped stickers on sealed jars this week as others checked on marijuana plants or carefully weighed buds.

“It would be a good problem to have if I couldn’t meet my demand,” said chief executive Armen Yemenidjian, whose Desert Grown Farms owns the only dispensary selling recreational pot on the Las Vegas Strip, across the street from the Stratosphere hotel.

Some dispensaries used social media to spread the word or tried to draw in buyers with special events. Some planned to give away free marijuana to their first 100 customers or throw parties with barbecues and food trucks later in the afternoon. Some facilities are in strip malls, while others, in stereotypical Las Vegas fashion, are in neighborhoods shared by strip clubs.

Deneal, 57, said she has a bipolar disorder and a bad neck. She said she never got a medical card for fear of a federal crackdown on those who provided their information to obtain it. Now, she said, she no longer has to fear being arrested for possessing marijuana.

“I’m going to spend the whole $100 bucks,” she said.