“Is this medicinal?” asked Senator Michael O. Moore, who then lifted up a jar filled with Purple Alien OG, smiling and posing for a photo on his phone.

“If I were to buy this, what would I do with it? Do I crush it? Roll it? Do I —” asked Senator John F. Keenan, pointing to a jar with a potent-smelling strain, his voice trailing off as if he weren’t sure of the other options.

DENVER — Standing in a retail marijuana dispensary Tuesday, amid cannabis-infused candy and big jars of “Sour Diesel” and “Bazooka Joe,” eight Massachusetts senators had some questions.


Later Keenan, a 51-year-old Quincy Democrat who opposes legalization and says he has never used the drug, had another query for a store employee: “Do you sell” — he paused — “the balm?”

The senators’ journey to RiverRock Cannabis, a marijuana cultivation facility and retail dispensary, is part of a crash course in the highs and lows of legalization in a state where adults have been able to openly buy recreational cannabis for more than two years.

The aim is to prepare the legislators for the barrage of complex issues that they’ll face if Massachusetts voters greenlight an expected legalization question on the November ballot.

“What we’ve learned is that while the implementation of legalized marijuana in Colorado has gone reasonably well, there are many, many different issues that come up and need to be addressed — some of which you can anticipate, and some of which” you can’t, said Jason M. Lewis, a Winchester Democrat, the leader of the trip, and the chairman of the special Senate committee on marijuana. “This trip will certainly help us reduce the number of unknowns.”

On Monday, the senators listened to the top medical official in the state’s public health department who said no large troubling public health trends had cropped up yet since legalization but noted sporadic reports of impaired driving and people getting sick from ingesting too much marijuana (or THC, the drug’s psychoactive compound) in edibles, such as candy bars.


A local police chief tersely advised the senators regarding the legalization process: “Slow it down.” And, via videoconference, they asked tough questions of Rick Garza, director of the Liquor and Cannabis Board of Washington state, one of four states and the District of Columbia where voters have legalized recreational marijuana.

A theme of senators’ questions has been the potential effect of legalization on children.

Garza said Washington has not seen a spike in youth consumption of marijuana since legalization but added some are concerned that adults being able to legally consume the drug normalizes it for kids.

That prompted a look of worry from Senator Linda Dorcena Forry, a Democrat from Dorchester. Later, she said she was struck by the importance of public service announcements and properly packaging marijuana edibles, such as brownies, to help prevent kids from accidentally ingesting the products.

Governor Charlie Baker, who strongly opposes legalization efforts, also weighed in on the issue Tuesday. He said he’s been told there have been emergency room visits and auto accidents associated with legal pot.

“And it’s a lot more about the edible stuff, which is sort of the corporatization of legalized marijuana,” Baker said on WGBH-FM.

When co-host Margery Eagan mentioned that she had eaten a “Rookie Cookie” made with pot during a visit to Colorado, Baker pounced.


“A Rookie Cookie!” he exclaimed. “Now is that directed at someone who is 21 or is that directed at someone who is, like, 12? We are heading right down the Joe Camel path on this. We really are.”

Mason Tvert, a spokesman for the Marijuana Policy Project, a national prolegalization group, said there is no evidence of any marijuana businesses marketing toward children.

He said if Baker is “truly concerned about the health and safety of children, he should want it to be sold in licensed stores that ask for ID and only sell to adults. Not on the street.”

Among the edible products at RiverRock were Cheeba Chews (“cannabis infused chocolate taffy,” the label said) and sour gummies.

Norton Arbelaez, a part-owner of RiverRock, which has two locations in Denver, emphasized that all the edibles sold in his stores are sold in child-resistant containers.

(Arbelaez, who helped organize much of Tuesday’s itinerary for the senators, is a consultant to New England Treatment Access, which has two registered medical marijuana dispensaries in Massachusetts.)

Also on Tuesday, the lawmakers visited a cannabis extraction, distillation, and purification facility in a snowy industrial park. Senator Viriato M. deMacedo, a Plymouth Republican, raised his eyebrows watching a gurgling machine that extracts THC and other potent compounds from cannabis buds or leaves.

He said prior to the visit, he had no idea about “the chemical aspect of this industry and the compounding” and indicated the whole trip, which runs through Thursday, has been eye-opening.


The group pushing a legalization question in Massachusetts has met the first and toughest signature-gathering requirement and is anticipated to put a statewide ballot question to voters in November that would legalize recreational marijuana use for those 21 and older.

The proposed legalization law would create a new “Cannabis Control Commission,” to oversee a system of marijuana stores, grow facilities, and manufacturers of edible products.

The measure would impose a 3.75 percent excise tax on retail marijuana sales, in addition to the state sales tax. It would also allow adults to grow up to six marijuana plants in their home, and it would give a leg up to medical marijuana dispensaries that want to become retail stores.

Massachusetts state Senator Michael J. Rodrigues snapped a photo at RiverRock Cannabis in Denver on Tuesday. Bob Pearson for The Boston Globe

Massachusetts legislators toured the RiverRock Cannabis marijuana facility in Denver. Bob Pearson for The Boston Globe/Boston Globe

The RiverRock Cannabis marijuana facility in Denver. Bob Pearson for The Boston Globe

Michael Levenson of the Globe staff contributed to this report. Joshua Miller can be reached at joshua.miller@globe.com. Follow him on Twitter @jm_bos. Click here to subscribe to his weekday e-mail update on politics.