yreka ( ) is the county seat of siskiyou county, california, united states. it is near the shasta river at 2,500 feet (760 m) above sea level and covering about 10.1 sq mi (26 km2) area, of which most is land. as of the 2010 united states census, the population was 7,765, reflecting an increase of 475 from the 7,290 counted in the 2000 census.