The Emerald Triangle refers to a region in Northern California which is named due to it being the largest cannabis-producing region in the United States. Mendocino County, Humboldt County, and Trinity County are the three counties in Northern California that make up this region. Growers have been cultivating cannabis plants in this region since the 1960s (during San Francisco's Summer of Love). The industry exploded in the region with the passage of California Proposition 215 which legalized use of cannabis for medicinal purposes in California. Growing cannabis in The Emerald Triangle is considered a way of life, and the locals believe that everyone living in this region is either directly or indirectly reliant on the marijuana business.