Martins Ferry is a former settlement in Klamath County and later in Humboldt County, California, United States. It lay on the Klamath River, at an elevation of . It still appeared on maps as of 1983.
History A post office operated at Martins Ferry from 1861 to 1862 and from 1865 to 1891. There was a military fort at the place in the 1860s. The name honors John F. Martin, its first postmaster, who also operated a ferry.
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