Unemployment levels are at a mere 3 percent in Denver today, and because of this employers are going to some surprising lengths to recruit new workers. The Employers Council ran a survey that found that, as of 2016, 10 percent of employers who screen for drug use have dropped cannabis from the list of substances they look for.

"It's because unemployment is virtually non-existent," Curtis Graves, a lawyer at the council told ABC7. "People cannot afford to take a hard line against off-duty marijuana usage if they want to hire."

These trends aren't specific to Colorado either. Across the country, filling jobs is more difficult now than it has been in nearly 20 years.

These changes largely don't have anything to do with new legislation. Yes, Maine has implemented protection for workers who partake in the legal recreational cannabis market, but in other legal states - like Colorado - employers still have the right to fire workers who test positive for cannabis use. Instead the move away from marijuana testing is being driven by sinking unemployment rates. And lawyers like Michael Clarkson who specialize in corporate drug testing say its only becoming more common.

"It has come out of nowhere," said Clarkson. "I have heard from lots of clients things like, 'I can't staff the third shift and test for marijuana.'"

Car dealership operator AutoNation is one of the few companies who has made a public statement about the changes in their drug policies. AutoNation spokesperson Marc Cannon says the shift was spurred by the change in public attitudes towards cannabis use, but also as a means to increase their potential labor pool.

"The labor market has tightened up."

Yet many other businesses who have stopped testing for cannabis use aren't being very forward about it, either to avoid stigma or to continue encouraging abstinence.

"We're doing the same thing," Cannon said other business leaders have told him. "We just didn't want to share it publicly."