Soon, two states that border Iowa will offer recreational marijuana for sale.

Illinois started selling pot to Iowans in January, while next year, South Dakota will begin to grow, tax and sell it. South Dakota voters approved an initiative on Tuesday allowing medical marijuana, and a constitutional amendment allowing recreational use.

Drey Samuelson, spokesman for South Dakotans for Better Marijuana Laws, says it was a big victory.  “Ten years ago, there was a medical marijuana initiative on the ballot and it lost two-to-one,” Samuelson says, “and a very similar initiative ten years later now passed by a margin greater than two-to-one. Attitudes are changing, just like people change.”

Both initiatives will take effect in South Dakota on July 1st of next year. Between now and then, that state’s legislature will have to determine how to launch and regulate the new industry, including whether people from neighboring states — like Iowa — may purchase the products.

“The question is whether or not people are going to get it legally and have it be safe and have it be taxed, where the revenue goes to our public schools and our state’s general fund,” Samuelson says, “or whether it’s going to be sold in a back alley and it’s not going to be safe, you don’t know what it is or how strong it is, and the profits go to organized crime and illicit drug dealers.”

Iowans can legally buy marijuana in Illinois and they can legally consume it there, but it’s illegal to bring the pot back to Iowa and to use it here. Also, Illinois residents can buy larger quantities of marijuana there than Iowans. South Dakota may go a similar route in how it treats non-residents.

Samuelson says the amendment was written to keep that state’s lawmakers from making changes to both the recreational and medical marijuana markets. “The good news is, Amendment A is a constitutional amendment and it protects Measure 26, the medical marijuana,” Samuelson says, “so the legislature can’t under it’s own volition change anything, frankly. They can mess with it around the edges, but they can’t repeal it.”

Sales in South Dakota will be limited to buyers who are 21 and older. This week, Arizona, Mississippi, Montana, and New Jersey also passed measures to legalize marijuana.

(Jerry Oster, WNAX, Yankton contributed to this report.)

Radio Iowa