DENVER—It's 8:30 in the morning, I've just left a recreational marijuana dispensary, and I'm desperate for my regular fix. Luckily, the waiter is quick to deliver it: Coffee. Black. No sugar.

Weed? Never had any interest. I managed to get through four years of college in the 1970s without once trying it, and I'm a little old to start going to Phish concerts.

In the meantime, columnist Maureen Dowd of The New York Times recently showed the dangers awaiting middle-aged scribes who sample the local specialties. She had a scary paranoid reaction after scarfing a cannabis-infused candy bar in her Denver hotel room.

I get my paranoia naturally, from the National Security Agency. So even though it's been perfectly legal to buy and consume cannabis here in Colorado since January 1, I'll stick to caffeine today.

I traveled to Colorado to indulge a more expensive and pointless escape than drugs (fishing), but as a journalist I feel some obligation to investigate important developments wherever they occur. After an old friend and I arrived in Estes Park one afternoon, we looked for a dispensary on our stroll down the main street.

Seeing none, I asked our dinner waitress, who said she didn't expect the town to ever get one. Why not? "Estes Park is pretty conservative."

The next evening, in the funky college town of Fort Collins, I figured my chances were better. But when I asked a young man on the street for directions to the nearest outlet, he regretfully informed me, "There aren't any yet. Denver is the closest place you could find one."

Fort Collins, it seems, is in thrall to another mind-altering substance. It produces 70 percent of the state's beer.

Not that pot is unavailable even back in Estes Park. After recounting my Fort Collins experience to friends over dinner a couple of nights later, I was stopped at the salad bar by a bearded guy with a resemblance to Johnny Manziel. "I couldn't help overhearing your conversation," he said softly, "and I just wanted to let you know I can provide whatever you need." Come to think of it, maybe it was Johnny Manziel.

But for a legal source, I had to go to Denver, which has dispensaries that open at 8 a.m. on Sundays, early enough to let us visit without missing our flights home. In Chicago, they don't let liquor stores open that early.

Once in the door, we got a warm greeting and a request for ID to confirm that I am at least 21 years old. "Come on in," said the smiling employees. "Take all the pictures you want." Really? People have been asked to leave Wal-Mart for doing that.

Inside was a small room with glass cases, where a tall salesman with scruffy whiskers brought out jars of cannabis, explained their different effects—"This is more of a heady high than a body high," whatever that means—and held them up for us to smell. (A sign says, "Please do not handle the jars or bud.") A couple of whiffs was enough to make my head hurt.

The staffer also showed us a small jar of Blue Kudu Chocolate, whose label says, "Semi-sweet chocolate with orange flavoring. Warning: Extremely potent. Do not eat all at once." Dowd must be one of those people who refuse to read food labels and never comprehend that corn chips are high in sodium.

I asked the clerk whether the shop ever has problems with the police. "The cops are our best friends," he replied. "They want this to work." He assured us that people drive better, not worse, when they're stoned, and predicted that marijuana will be legal nationally in a year. Whatever he was smoking must be really good.

We went out and into the "Garden Viewing Corridor," which afforded a view of rooms full of plants under lights that cast a faint lavender glow. To me, it resembled an ordinary nursery. But of course this is not an ordinary establishment. It's a legal outlet for a recreational drug that has long been the target of prohibition.

An affable security guard dressed in shorts and a T-shirt told me he likes working there. "I worked in a psych ward before, and this is a lot easier," he said. Ever have trouble with customers? "The only problem we have here is people coming in drunk."

Got that? At the cannabis dispensary, the people you have to watch out for are the drinkers.