▁of ▁FM ▁ 2 0 4 8 ▁at ▁the ▁McC ul lo ch - San ▁S aba ▁County ▁Line . ▁Later ▁that ▁day , ▁FM ▁ 2 0 4 8 ▁was ▁cancel led ▁and ▁combined ▁with ▁FM ▁ 5 0 2 . ▁ ▁FM ▁ 5 0 3 ▁ ▁FM ▁ 5 0 3 ▁was ▁designated ▁on ▁July ▁ 1 4 , ▁ 1 9 4 5 , ▁from ▁US ▁ 8 7 ▁ 2 . 5 ▁miles ▁north west ▁of ▁Mel vin ▁north ward ▁ 7 . 4 ▁miles ▁to ▁Salt ▁G ap . ▁On ▁November ▁ 2 3 , ▁ 1 9 4 8 , ▁FM ▁ 5 0 3 ▁extended ▁north ▁ 6 . 2 ▁miles ▁to ▁Do ole . ▁On ▁November ▁ 2 1 , ▁ 1 9 5 6 , ▁FM ▁ 5 0 3 ▁extended ▁north ▁ 6 ▁miles ▁to ▁St acy . ▁On ▁September ▁ 2 7 , ▁ 1 9 6 0 , ▁FM ▁ 5 0 3 ▁extended ▁north ▁to ▁US ▁ 6 7 , ▁replacing ▁FM ▁ 5 6 6 . ▁On ▁May ▁ 6 , ▁ 1 9 6 4 , ▁FM ▁ 5 0 3 ▁extended ▁north ▁to ▁FM ▁ 5 3 ▁( now ▁SH ▁ 1 5 3 ). ▁On ▁May ▁ 7 , ▁ 1 9 7 4 , ▁FM ▁ 5 0 3 ▁extended ▁north ▁ 2 . 4 ▁miles ▁to ▁its ▁current ▁termin us . ▁ ▁FM ▁ 5 0 4 ▁ ▁FM ▁ 5 0 4