San Bernardino and Riverside are two of the largest counties by area in the United States, making up more than 10% of the population of the state of California, and encompassing over 27,000 square miles with more than 4 million residents.

The work of Catholic Charities in the two counties extends from the eastern valleys of the Los Angeles basin to the Nevada and Arizona borders, and includes sprawling metropolitan areas, extensive suburban developments, rural agricultural pockets, and tiny communities scattered throughout a very large unincorporated and isolated desert.