▁was ▁designated ▁on ▁July ▁ 1 4 , ▁ 1 9 4 5 , ▁from ▁US ▁ 2 8 3 ▁west ▁and ▁south ▁ 3 . 5 ▁miles ▁through ▁L ohn ▁to ▁a ▁point ▁ 5 ▁miles ▁east ▁of ▁Pear ▁Valley . ▁On ▁July ▁ 2 1 , ▁ 1 9 4 9 , ▁FM ▁ 5 0 4 ▁extended ▁west ▁ 2 . 8 ▁miles . ▁On ▁May ▁ 2 3 , ▁ 1 9 5 1 , ▁FM ▁ 5 0 4 ▁extended ▁west ▁ 3 . 2 ▁through ▁Pear ▁Valley ▁to ▁a ▁road ▁intersection . ▁On ▁November ▁ 2 0 , ▁ 1 9 5 1 , ▁FM ▁ 5 0 4 ▁extended ▁west ▁ 3 . 1 ▁miles . ▁On ▁December ▁ 1 7 , ▁ 1 9 5 2 , ▁FM ▁ 5 0 4 ▁extended ▁west ▁ 2 ▁miles ▁to ▁FM ▁ 5 0 3 . ▁ ▁R M ▁ 5 0 5 ▁ ▁R M ▁ 5 0 5 ▁lies ▁entirely ▁within ▁Jeff ▁Davis ▁County ▁in ▁the ▁Trans - P ec os ▁region ▁of ▁far ▁West ▁Texas . ▁Int ended ▁to ▁provide ▁a ▁link ▁between ▁the ▁county ' s ▁only ▁two ▁incorpor ated ▁areas , ▁Valent ine ▁and ▁Fort ▁Davis , ▁R M ▁ 5 0 5 ▁begins ▁at ▁a ▁j unction ▁with ▁US   9 0 ▁south ▁of ▁Valent ine ▁and ▁travel s ▁about ▁ ▁east ▁to ▁an ▁intersection ▁with ▁SH   1 6 6 ▁approximately ▁ ▁west ▁of ▁Fort ▁Davis . ▁ ▁FM ▁