It's Saturday morning at an "entrepreneurship retreat" at a hotel in Aurora, Colorado, just outside Denver - well, that's what the sign in the lobby reads anyway.

The word "marijuana" is conspicuously absent from the marquee.

Social media is abuzz over 4/20, the unofficial holiday celebrating all things marijuana, including its consumption. As pot fans across the country commemorate National Weed Day, restaurants in states such as California and Colorado and even in the nation’s capital are promoting 4/20 specials and deals in hopes of luring hungry smokers with cheaper eats. Some dispensaries in those states and others with legal weed are offering discounts or even freebies to certain customers.

Understand that Las Vegas is not the town it claims to be.

If you’re an adult in Las Vegas, you can do almost anything. On the strip, you can smoke, drink, and gamble. Drive an hour in one direction, and you can fire heavy weapons, legally. Drive an hour in another direction, and you can pay for sex, legally. But if what helps you relax is a prescribed dose of medicinal marijuana, you’re out of luck.

Marijuana policy has emerged as a key issue in American politics, particularly over the past few years. The issue is being debated at local, state, and federal levels, and has captured the attention of media organizations and research institutions nationwide and around the world.

Navigating the policy terrain and understanding what is happening in this fast-paced, dynamic, and changing arena is often tough. Knowing who is influential can be even more difficult. Because of the expansive nature of the policy conversation there are hundreds of key players making a difference—on both sides of this issue—and that list is seemingly ever growing.

Marijuana connoisseurs may soon have a new option for finding the best weed: brain scans.

In the past, the marijuana selection process went something like this: buy whatever your dealer offers. If you're lucky, you can choose between strains with vaguely evocative names like Blue Dream and Romulan. Then, with the advent of medical marijuana dispensaries, selection became more refined. All of a sudden, that Blue Dream comes with information on its percentage of THC (the ingredient that gets you high) and CBD (the pain relief ingredient).

Between 2012 and 2050 the United States will experience a considerable increase in its older population, with aging baby boomers largely contributing to that growth. American’s graying population has wide-ranging implications for the legal cannabis industry, which grew from $1.5 billion in 2013 to $2.7 billion in 2014.

PHOENIX — Arizonans could get to decide next year if they want to follow the lead of Colorado and Washington and let any adult buy and use marijuana.

An initiative drive launched Friday would treat marijuana like alcohol, which includes creating a state regulatory agency with its own police powers and a 15 percent tax.

The money would pay for the oversight and, according to backers, potentially raise between $60 million and $100 million, mostly for education, but with some for health care.

But they first have to get the issue on the 2016 ballot. That means gathering 150,642 valid signatures by July 7, 2016.

There was a time when the term 4/20 drew either blank stares or giggles. The term, which refers to marijuana, has become more mainstream in recent years and April 20, once considered a counterculture holiday, is actually trending on Twitter. The reality is that marijuana doesn’t have the same taboo as it did before. That’s largely thanks to legalization.

DENVER (TheBlaze/AP) — Denver police said there were no major problems as marijuana celebrations continued for a second day on Sunday, but police tweeted a reminder that while recreational use of marijuana is legal in Colorado, people still can’t use it in public.

We’d prefer not to be buzzkills this 4/20 weekend. #ConsumeResponsibly, and designate a sober driver now. #Denver

— Denver Police Dept. (@DenverPolice) April 19, 2015

Today is April 20, aka 4/20, the semi-official annual holiday for the marijuana industry and pot-enthusiasts around the world.

People flock to public celebrations across the country that, in some cases, attract crowds of thousands. Pot-related businesses also show off their products.