ˌoʊvɚ ðə fˈɑːloʊɪŋ θˈɜːɾi fˈaɪv jˈɪɹz ðə pˈɑːɹk wʌz ɡɹˈædʒuːəli ɛkstˈɛndᵻd, ænd wʌz ɹᵻnˈeɪmd ðə saʊθwˈɛst nˈæʃənəl pˈɑːɹk, fˈaɪnəli ɹˈiːtʃɪŋ ɪts pɹˈɛzənt sˈaɪz ɪn nˈaɪntiːnhˈʌndɹɪd nˈaɪnti.
Over the following 35 years the park was gradually extended, and was renamed the Southwest National Park, finally reaching its present size in 1990.