- Yreka is a city located in Siskiyou County, California, United States. It is situated in the Shasta Valley at the base of the Siskiyou Mountains. The city has a population of approximately 7,800 people. Yreka is known for its historical charm and its location as a gateway to outdoor recreational activities such as hiking, fishing, and skiing. It has a rich history rooted in the California Gold Rush and is home to several historic buildings and museums. Yreka has a small-town feel with a close-knit community and a downtown area with various shops, restaurants, and parks.