Mexicali Municipality is a municipality (Spanish: municipio) in the Mexican state of Baja California. Its municipal seat (Spanish: cabecera municipal) is located in the city of Mexicali. As of 2010, the municipality had a total population of 936,826, and according to the 2000 census, it had 764,602 inhabitants. The municipality has an area of 13,700 km² (5,300 sq mi.) This includes many smaller outlying communities as well as the city of Mexicali. Also, the islands of Baja California located in the Gulf of California are part of the municipality, among them the mudflat islands at the mouth of the Colorado River (the largest one being Montague Island), Isla Ángel de la Guarda and the islands of the San Lorenzo Marine Archipelago National Park. Mexicali is the northernmost municipality of Latin America.

The city of Mexicali was founded in 1903, and its name is a portmanteau of Mexico and California, as is the name of Calexico, California across the border.

The municipality of Mexicali, is divided into 14 administrative boroughs (Spanish: delegaciones) of which the city of Mexicali occupies 3 beside the city proper area; all boroughs are in turn divided into colonias or ejidos. These boroughs offer administrative services such as urban planning, civil registry, inspection, verification, public works and community development and are served by a delegado.

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