sentences:  Tam) encompasses more than 10 square miles of public land and open space, and is the primary source of drinking water for 75% of Marin's population.Established in 2014, the Tamalpais Lands Collaborative (TLC) combines the resources, skills, and expertise of the Golden Gate National Parks Conservancy, National Park Service, Marin Municipal Water District (MMWD), California State Parks, and Marin County Parks to preserve these protected public lands.In November 2014, the TLC launched the One Tam Initiative to help raise awareness of the preservation efforts needed to secure Mt.