In 2002 the San Gabriel Valley Task Force of the Angeles Chapter of Sierra Club in Southern CA realized there was the possibility of creating a 17 mile long loop of bicycle, equestrian and walking trails connecting the San Gabriel River, the Rio Hondo, and the Whittier Narrows region of parks and the local Nature Center. Volunteer members and a staff member walked this entire route to see what was there. Were there opportunities for new parks or access to the river trails from residential areas? The idea was to create a system of parks and trails that could serve the 500,000 people living nearby and residents throughout the SoCal region while enhancing the habitat for plants and animals.
Sierra Club also sponsored a series of studies that suggested opportunities existed to develop parks ranging from small pocket parks to larger neighborhood parks in underused areas. Opportunities were also found for educating the public about the rivers and the historical changes that have occurred along them.
Trails were already along the rivers from the mountains to the coast but were not a pleasant ride and the trails were not connect-ed between the two rivers—the “clasp” of the necklace. Thus was born the concept of the Emerald Necklace, with a chain of green parks and the pendent in the Whittier Narrows where areas of parkland with lakes and a Nature Center were already present with a clasp cutting across through Irwindale in the region of the gravel pits.
The concept has evolved through work of the Watershed Conservation Authority, Amigos de los Rios (a group that originated with the this Task Force), and the Sierra Club.