Founded in 1916 as the Coronado Council, and the San Diego Council, in 1917 the two councils merged to make the San Diego County Council (#049). Founded in 1922, the Imperial County Council (#029) changed its name to Imperial-Yuma Area Council in 1929, and changed the name again in 1959 to Desert Trails Council. In 1993 Desert Trails and San Diego County merged to become Desert Pacific Council. Desert Pacific Council was renamed to San Diego-Imperial Council on January 3, 2005.
For brevity, in 2015, the area of Vista to Borrego Springs was covered by a few districts that included:
*Kit Carson District
*Pacific Crest District
*Santa Margarita District
In 2016, the the area of Vista to Borrego Springs districts were modified and changed to:
*Buena Creek District
*Desert Trails District
*Palomar Mountain District
During the summer of 2020, major new changes in San Diego-Imperial Council Districts took place in North San Diego County and the geographical areas formerly known as Districts was removed with Zones established with new Zone geographical boundaries lines implemented.
Buena Creek District, Palomar Mountain District and a portion of the Desert Trails District became the Palomar Zone becoming the largest Zone in the Council covering a territory and the communities from Vista to Borrego Springs as noted on the map below.
October 1, 2023, San Diego – Imperial Council announced that all Zones will now be called Districts and no boundary lines will change.