The annual winter population is 177,570 in Central Coast, 233,394 in the state
—The Central Coast is favored by the Western monarch butterfly, with 76% of the state’s population in San Luis Obispo and Santa Barbara counties. The best places to visit the monarchs in San Luis Obispo County are at the Pismo State Beach Monarch Grove, with 16,038 butterflies reported, and the grove at Morro Bay State Park, with over 10,000 butterflies.
The Western monarch migrates from overwintering sites along California’s coast inland, all the way into Canada and back to coast every year. The populations at the various California overwintering sites are counted every year in November and December by the Xerces Society for Invertebrate Conservation.
The Pismo State Beach Monarch Grove is one of California’s principal overwintering sites for the monarch. The butterflies can be seen hanging in clusters on the eucalyptus trees in the grove and now and then, a few will flutter around, adding a sense of a magical wonderland to the grove.
Western Monarch Trail. Officially launched on Earth Day in April 2022 when the first interpretive panels were installed in the park, the Western Monarch Trail follows the migration route of the monarch butterfly through California and other western states. The panels at the Pismo Beach monarch grove, in Spanish and English, provide information about the monarch butterflies and what we can do to help preserve and restore the population. Experts in the field and representatives of participating organizations have all collaborated to create beautiful and informative panels.
The declining monarch butterfly population has been a concern for scientists and butterfly enthusiasts since 2014 when a dramatic decline was observed in Eastern monarch butterflies hibernating in Mexico. Scientists attribute the decline to the disappearance of the monarch milkweed plant, the only plant the monarch caterpillar will eat. Statewide 1995 butterflies were counted in January 2020, a chilling drop from the millions of Monarchs that used to overwinter at various California sites.
Monarch butterflies leave their overwintering sites in the spring to breed and migrate north as far as Canada. They breed and hatch several generations on their way north, each generation living only a short time except for the last generation, which returns to their overwintering groves. The Western Monarch overwinters along the California Coast. The Monarch butterflies that overwinter in Mexico migrate through the eastern United States, then return to Mexico.
The best spots to see and learn more about the Monarch butterfly on the Central Coast are the Pismo Beach Butterfly Grove and the grove at Morro Bay State Park.
Visitors to the grove at Pismo State Beach, located just off State Highway 1, are greeted by knowledgeable and well-informed volunteer docents offering talks and information about the butterflies visiting the grove.
The Pismo State Beach Monarch Grove is located at 400 S Dolliver St, Pismo Beach. For more information visit parks.ca.gov.