OREGON: Oregon Gov. John Kitzhaber Wednesday signed a bill legalizing medical marijuana retail establishments.

The law, which moves Oregon’s booming medical marijuana industry into the mainstream, creates a registry of businesses that sell the medical marijuana.

Patients have long sought retail access to cannabis, arguing the state’s rules — grow your own marijuana or have someone do it for you –€” are unrealistic.

The law comes a year after an investigation by The Oregonian showed that scant state regulation of medical marijuana allowed widespread diversion to the black market. Oregon joins a dozen other states that allow medical marijuana dispensaries or retail outlets.

Here’s a detailed Q&A about the new law.