The huge underground cannabis economy was woven into the commercial fabric of California long before the 2016 passage of Proposition 64, which legalized marijuana for adult use. Transforming a shadowy, multibillion-dollar industry into a heavily taxed and regulated structure presents unique and enormous challenges. Who will gain and who will lose under the new regime? Will the expected financial dividend from legalization be broadly distributed throughout the Golden State? California’s cannabis regulations are supposed to accomplish two key objectives: Curtail illicit sales and rein in extensive harm to the natural environment caused by black market growers. But the way legalization is being implemented could have the opposite effect. Steep taxes, higher operating costs, and an insatiable out-of-state demand for California cannabis all but ensure that the black market will survive – if not thrive – in the near term and ecological abuse will continue, as Angela Bacca reports in this special, three-part series.