While it may not be traded on Wall Street any time soon, marijuana has become a booming cash crop. CNBC's Trish Regan goes behind the scenes to explore the inner workings of this secretive industry, focusing on Northern California's "Emerald Triangle," now the marijuana capital of the U.S. In this scenic pocket of America, the pot business, much of it legal under state law, now makes up as much as two-thirds of the local economy.