However , the closure of Amarillo Air Force Base on December 31 , 1968 , contributed to a decrease in population to 127,010 by 1970 .
Between 1950 and 1960 , Amarillo 's population grew from 74,443 to 137,969 .
The closure of Amarillo Air Force Base on December 31 , 1968 , contributed to a decrease in population to 127,010 by 1970 .
Between 1950 and 1960 , Amarillo 's population grew from 74,443 to 137,969 .