An early inkling of the commercial potential of marijuana tourism came on a day with a mythical significance for many marijuana users: April 20, 2014, when one travel booking site saw searches for Denver jump nearly 75% year-over-year months after recreational marijuana use was legalized in Colorado.

It happened again this year, according to online hotel booking service Hotels.com, with April 20 searches — “420,” a slang term for marijuana, is linked to 1970s youth and drug culture in northern California — increasing in Colorado but also Washington, where recreational marijuana was legalized in July 2014, and Oregon, where it became legal this July.

My 420 Tours

Recreational marijuana use is now legal in Colorado, Washington, Oregon, Alaska and the District of Columbia. It has been legalized for medicinal use in 23 states and the District of Columbia, where it is used to treat pain, nausea and other conditions; health experts, however, warn that overconsumption can lead to increased heart rate, delayed response rate and feelings of paranoia or anxiety.

Tourist interest in states and cities where it is legal to buy and consume cannabis without a medical license has increased, according to Hotels.com search data, and new industries are seeking to serve those travelers.

But while entrepreneurs increasingly see an opportunity to grow a new offshoot of the travel industry, complications still exist, likely restraining the industry’s early growth. (Federal law prohibits marijuana, though the Obama administration has generally left enforcement to the states.)

“It’s hard to know where people are able to use” marijuana, said David Blandford, a spokesman for Visit Seattle. “There are legal and enforcement questions. It’s a tricky proposition.”

Even in states where recreational marijuana is legal, it is prohibited to smoke in public, and most hotels don’t allow smoking in rooms. Seattle’s proximity to the Puget Sound and Lake Washington, meanwhile, has created confusion for local law enforcement regarding the legality of its use on boats near the Canadian border, according to Blandford.

Advertising and interstate commerce raise other concerns. In Washington state, it is illegal to advertise marijuana products within 1,000 feet of schools and other areas that cater to children, or to place product advertisements on a publicly owned or operated property. It is also illegal to transport cannabis across state borders.

Visit Seattle is worried that tourists or marijuana businesses might run afoul of those laws. “It’s a concern,” said Blandford. “It’s a big question mark on our end.”

Other states are proceeding cautiously in their efforts to market themselves to would-be marijuana tourists.

“As of July 1, it became legal to smoke pot recreationally, but there were no distribution channels,” said Linea Gagliano, a spokeswoman for Travel Oregon. “Unless you’re growing it on your own, there’s no way to consume it.”

New state regulations are expected to make legal distribution easier, Gagliano said, but the questions about public consumption and advertising remain. Consequently, Oregon has not begun heavily marketing itself as a destination for marijuana enthusiasts, focusing instead on its culinary and natural attractions.

“For now, we’re going to stick with those things that we know are compelling reasons to visit Oregon,” Gagliano said.

Despite the challenges in these states, companies are finding ways to capitalize on the newfound interest in marijuana-related tourism.

My 420 Tours, founded in 2013, gave its first tour during World Cannabis Week, a festival in Denver during the week of April 20 — “The New Year’s of Cannabis,” according to Chief Operating Officer Danny Schaefer. (The term “420” originated in the early 1970s in San Rafael, Calif., when a group of teenagers decided to meet regularly at 4:20 pm to search for an abandoned plot of marijuana plants.)

The company provides tours including transportation, hotels and activities including dispensary tours and cannabis cooking classes. Schaefer says My 420 Tours has partnerships with hotels that allow marijuana use so tourists can try recreational marijuana without worrying about public-use laws. All-inclusive tours start at $1,295 per person, not including airfare.

“On our tours, visitors can safely and legally consume cannabis, as well as get an education and experience what has happened here in Colorado,” Schaefer said.

He estimates that My 420 Tours hosts about 300 to 600 guests per month, depending on the season. About 70% of tour visitors are traveling to Colorado for the first time, and include frequent consumers, first-timers, people celebrating retirement and potential marijuana entrepreneurs and investors. “We have a mix of guests from all over the world,” Schaefer said.

To avoid any issues of interstate commerce, Schaefer says My 420 Tours collects leftover cannabis from guests before they arrive at the airport. The extra marijuana is then donated to nonprofit organizations for demonstration or education purposes.

American Cannabis Partners, a marijuana entrepreneurship consulting firm, is opening Colorado’s first “weedery,” entering the popular winery and brewery tourism market. The $35 million Colorado Cannabis Ranch & Amphitheater, slated to include open-air greenhouses, a dispensary, a gift shop, an amphitheater for musical performances and community classes, and a rooftop bar and restaurant, is scheduled to break ground in Denver in the fourth quarter of 2015.

ACP founder Christian Hageseth came up with the idea after realizing how much money growers were spending on the electricity to power indoor growing warehouses.

“In Colorado we’re blessed with 300 days of sunshine a year,” Hageseth said. “Warehouses are just recreating the sun. It’s really expensive.”

Additionally, Hageseth said that as a longtime grower, he saw an opportunity to take advantage of the curiosity surrounding the young industry.

“People [unfamiliar with marijuana] have always asked a lot of questions about the industry,” Hageseth says. “A lot of aspects of what it means to grow marijuana in a hydroponic environment blew people away. People’s minds were changing. They were really opening up to the fact that marijuana is just a plant.”

The company is optimistic: It expects to generate just over $90 million in revenue from the weedery during the first few months of operation.

Because of current Colorado public use laws, weedery visitors will not be allowed to smoke on the property, but they can buy cannabis products on site.

Hageseth hopes the weedery will attract a variety of customers, as well as become a hub for community events like yoga classes and musical performances.

“We want to be open and accepting of everybody from all walks of life,” he said. “We hope that a group of people can form their own opinion on marijuana from an enlightened perspective. Prohibition has cast a shadow on the opinion of what marijuana really is.”

He adds that he has been exploring sites for similar projects in Nevada, Hawaii and Massachusetts, which have all legalized medical marijuana.

“We may be the first, but we certainly won’t be the last,” Hageseth says. “The hope is that weederies become as popular as wineries and breweries.”