How many people lived in the Spanish missions and forts?

During the Spanish era most of the inhabitants lived in one of the four presidios (San Diego, Monterey, San Francisco and Santa Barbara), one of the three pueblos or towns (San Jose, Los Angeles and Branciforte) or at one of the missions.

The best source for the population data is the annual reports prepared for the authorities each year. Dr. Robert Jackson has assembled data from these annual reports and was good enough to provide me with these counts for the year 1820, just before Alta California became part of Mexico.

ALTA CALIFORNIA 1820
 
LOCATION POPULATION
Presidios 2,086
Pueblos (Towns) 976
Missions 21,063
TOTAL 24,125