ɐ pɹˈiːviəs ɹˈaʊt nˈʌmbɚd ˌɛsˈeɪtʃ ˈeɪɾi fˈoːɹ wʌz dˈɛzɪɡnˌeɪɾᵻd ˌɔn ˈɔːɡəst twˈɛnti wˈʌn, nˈaɪntiːnhˈʌndɹɪd twˈɛnti θɹˈiː, æz ɐ ɹˈaʊt əkɹˌɑːs wˈɛst tˈɛksəs fɹʌmðə nˈuː mˈɛksɪkˌoʊ stˈeɪt lˈaɪn θɹuː bɹˈaʊnfiːld ænd pˈoʊst tə dʒˈeɪtən, ɹᵻplˈeɪsɪŋ pˈoːɹʃənz ʌv ˌɛsˈeɪtʃ ˈeɪtiːn ænd ˌɛsˈeɪtʃ θˈɜːɾi nˈaɪn.
A previous route numbered SH 84 was designated on August 21, 1923, as a route across West Texas from the New Mexico state line through Brownfield and Post to Jayton, replacing portions of SH 18 and SH 39.