'Riverside County, CA' definitions:

Riverside -- U.S. County in California

From: Gazetteer 2000
Name :
Riverside -- U.S. County in California
Population (2000) :
1545387
Housing Units (2000) :
584674
Land area (2000) :
7207.369000 sq. miles (18666.999221 sq. km)
Water area (2000) :
95.760818 sq. miles (248.019369 sq. km)
Total area (2000) :
7303.129818 sq. miles (18915.018590 sq. km)
Located within :
California (CA), FIPS 06
Location :
33.783307 N, 116.803605 W