It’s official: Nearly three years after the state legalized medical marijuana, New Hampshire’s first dispensary will start serving patients Saturday morning in Plymouth.

This afternoon, the Department of Health and Human Services announced that it issued a registration certificate to Sanctuary ATC — which means they’ve completed the state inspection process and can now open to the public.

Moments after DHHS made the announcement, Sanctuary ATC followed up with its own announcement — saying it plans to open its doors at 11 a.m. on April 30.

Sanctuary ATC is one of three companies selected to run four dispensaries for New Hampshire’s medical marijuana program.

(For more on the years-long process leading up to the dispensary launch, check out our past reporting here. You can also check out this map of dispensary locations in New Hampshire and neighboring states.)

Another one of the dispensary companies, Temescal Wellness, is also on track to open its two locations soon, according to Martin. Temescal’s Dover location could be licensed as early as next week, Martin said, and its Lebanon location could be ready within the next few weeks, too.

The remaining dispensary, to be operated by Prime ATC in Merrimack, might take longer. It hasn’t yet received approval from the state to start growing cannabis at its cultivation site.

There are a few reasons for the delay there, Martin said: The company ended up moving its cultivation site to a new location earlier this year, which set its timeline back a bit, and that site is also on track to be the largest one in the state.

Martin said Prime ATC has signaled that it could be ready to have its cultivation site inspected sometime in May.

“With a little bit of luck, we’ll be able to issue them a conditional registration certificate sometime next month,” Martin said.

As of April 29, 613 patients and 39 caregivers have been approved for New Hampshire’s medical marijuana program, according to figures provided by the state. A little over 800 people have applied so far, and only three patients have been denied.

The remaining unapproved applications “were incomplete as submitted,” Martin said — but the state tries to notify someone if their application is incomplete and gives them an opportunity to correct the forms.

Patients can only register to buy medical marijuana from one dispensary at a time. Someone can switch their chosen dispensary if they change their mind after registering.

So far, Sanctuary ATC’s location in Plymouth — New Hampshire’s northernmost dispensary — is the most popular. As of this week, 147 people have signed up there.

“I’m really surprised by the numbers in the North Country,” Martin said. “We really wondered if there were going to be enough patients in the North Country to sustain an alternative treatment center.”

Another 136 people have signed up with Prime ATC’s dispensary in Merrimack. A combined 170 people have signed up with Temescal Wellness,108 in Dover and 62 in Lebanon.

(These figures only include patients who’ve received their medical marijuana ID cards from the state. Patients who’ve been approved for the program but haven’t received their ID cards aren’t included in that total.)

As it stands, there aren’t any plans to add another set of dispensaries — but Martin said it could be beneficial to allow the existing dispensaries to open up more locations in New Hampshire.

That way, he suggested, a dispensary could open up another location in the North Country or in the area around Keene, which is also fairly isolated from the existing dispensary locations.

“The idea of allowing each alternative treatment center to have one additional satellite just makes so much sense,” Martin said.