Oklahoma comes from the Choctaw words okla ('people') + humma ('red'), meaning 'red people.' The state was largely settled during the Land Run of 1889 and is famous for tornado alley and 1995's Oklahoma City bombing.
memory
Sound-mapping: 俄 (é) for 'O-', 克 (kè) for '-kla-' (with 拉 lā), 何 (hé) for '-ho-', 马 (mǎ) for '-ma'. The five chars trace each English syllable.