A seismic risk evaluation was conducted on a site near Eureka, California. The site was subject to potential earthquake loading from a number of sources. These sources were: (1) Mendocino Fracture Zone, (2) Gorda Segment of the Cascadia Subduction Zone, (3) Little Salmon thrust fault under the site, (4) Mad River Fault Zone, and (5) Intra plate west - Gorda Plate. The geology of thrust faults in Northern California is examined along with that of the Mendocino Fracture Zone, and the southern section (Gorda Segment) of the Cascadia subduction zone. A trench log showing a splay of the Little Salmon Fault is presented. A seismic risk analysis of the site was performed using recurrence curves for the various seismic sources estimated from both trench studies and historic seismicity. Using this information the acceleration at the site due to the Maximum Credible Earthquake is estimated to be 0.85g. The corresponding acceleration due to the Maximum Probable Earthquake and assuming that the various fault zones act independently or co-seismically is estimated to be 0.5g
