South Dakota just legalized both medical and recreational cannabis. Here's what you need to know.

• South Dakotans just voted to legalize both medical and adult-use cannabis.
• It's the first time a state has voted in favor of both medical and recreational cannabis at the same time.
• The state will allow adults over the age of 21 to possess up to 1 ounce of cannabis and also create a medical-marijuana program.

South Dakota joined a slew of states where voters backed measures on Tuesday to legalize cannabis.

South Dakotans voted to create a medical-marijuana program and to legalize cannabis for all adults over age 21, according to vote counts from Decision Desk HQ.

It could take some time before South Dakotans can purchase marijuana in the state. State lawmakers and regulators have until April 2022 to craft cannabis rules, such as for dispensaries.

It was the first time that a state has voted in favor of both medical and adult-use programs at the same time.

"South Dakota is the most conservative state yet to legalize marijuana and it passed both medical and recreational on the same ballot, something that's never been done before," said Matthew Schweich, deputy director at Marijuana Policy Project, a non-profit focused on cannabis reform in the US.

People will be allowed to possess up to 1 ounce of cannabis for recreational use, per the text of Amendment A.

In the medical program, patients with "debilitating medical conditions" would be allowed access to cannabis after receiving registration cards from the Department of Health, according to the language in Measure 26.

Patients with a chronic condition such as debilitating pain, severe nausea, and seizures could get cannabis after receiving a recommendation from a healthcare professional. The Department of Health has the power to add other conditions to the list. Patients would be allowed to possess up to 3 ounces of cannabis in addition to other cannabis products.

Measure 26 tasks the Department of Health with laying out the rules for the state's new medical cannabis program by October 29, 2021 and medical cannabis cards are to be issued by the agency 140 days after that. Recreational cannabis

Recreational cannabis sales will be taxed at 15%, and the funds would be used to cover the program's costs and to fund public schools and the state's general fund.

Read the ballot measures directly here (Measure 26 - medical) and here (Amendment A - recreational).

Read more: The ultimate guide to marijuana legalization: All the states voting on cannabis reform in November, the probability of success, and which stocks could benefit the most