Six years ago recreational marijuana use was illegal in all 50 states — and had been for nearly a century. Following the 2018 midterm elections, anyone over 21 will soon be allowed to legally consume marijuana in 10 states plus the District of Columbia. Overall, 33 states in the past 22 years have passed some form of marijuana legalization, from medical to recreational use.

Despite the ever-present federal threat — the Drug Enforcement Administration still considers marijuana a banned substance, and former Attorney General Jeff Sessions threatened a crackdown — the $8.5 billion U.S. marijuana industry seems poised to grow as rapidly as the law will allow it. And it's generating jobs just as quickly.

By 2020 the industry is expected to create 250,000 new jobs, according to New Frontier Data, an industry research firm. In 2017 the number of job posts for openings in the marijuana industry increased by 445 percent, outpacing tech (254 percent) and health care (70 percent), according to ZipRecruiter.

The industry is in search of workers across the spectrum, from accounting to compliance, customer service, sales, technology and more. As the industry grows, so too do the opportunities. California, Colorado and Washington currently have the greatest demand for workers, but that could shift as legalization spreads.

Though the total number of marijuana jobs are still far smaller than those other, much older industries, they include several positions that didn't exist prior to legalization, offering enterprising workers the opportunity to get in on the ground floor of an entirely new career.

Because legalization has come state by state, there is no single association or governing body offering licenses, training or certifications. Workers looking to enter the industry will need to do a bit of research to find out their specific state requirements.

But newcomers don't necessarily need an encyclopedic nature of weed culture to succeed in the industry. In fact, Karson Humiston, CEO and founder of recruiting firm Vangst, said she decided to start her firm, which specializes in the cannabis industry, after discovering the breadth of talent required by entrepreneurs attending a 2015 industry convention.

"When I asked people what positions they were hiring for, it was everything from a botanist to a chemical engineer to a Ph.D. to a retail store manager to a marketing manager to a human resource manager to a CFO," she said. "You name it, and these companies were hiring for it."

Though some may hesitate to join an industry selling a drug that's still banned by federal law, everyday workers have little to fear, said Morgan Fox, media relations director for the National Cannabis Industry Association. "We haven't seen any U.S. attorneys make an effort to crack down on businesses that are compliant with state law, even though the former attorney general gave them carte blanche to do so," he said, referring to Sessions. "If someone is just an employee of a company, I would think there's pretty much no risk."

Here are five fast-growing new careers driven by marijuana legalization. Salary data is gleaned from the 2018 Vangst Salary Guide. In most cases the salary ranges are unusually broad due to the industry's youth and rapid expansion.