NOVEMBER 23, 1873 (M=6-3/4)
[c6, p169]

The severe earthquake of November 23, 1873, was felt from San Francisco to Portland, Oreg.; it inflicted the heaviest damage to Crescent City, Calif., and surrounding communities in the Klamath Mountains. The macroseismic epicenter near the California-Oregon State line and probably inland of the coastline is unique within both the historical and instrumental records.