Whitman County is a county located in the U.S. state of Washington. As of the 2000 census, the population was 40,740. The county seat is at Colfax.
History
Whitman County was formed out of Stevens County on November 29, 1871. It is named after Marcus Whitman, a Presbyterian missionary who, with his wife Narcissa, was killed in 1847 by members of the Cayuse tribe.