Thousands of marijuana farms are depleting California's streams at the height of a historic drought, according to state scientists. Special correspondent Spencer Michels follows along as game wardens, biologists and engineers go in search of marijuana on privately-owned lands --…

Attending a conference for cannabis entrepreneurs and potential investors, Paul Solman heard the latest product pitches and saw the newest paraphernalia. But what about the people behind this growth industry -- what's their relationship to the substance? For some, it's…