ɐ nˈaɪntiːnhˈʌndɹɪd nˈaɪnti θɹˈiː fˈɔːɹɪst sˈɜːvɪs stˈʌdi ˈɛstᵻmˌeɪɾᵻd ðætðɪ ɛkstˈɛnt ʌv ˈoʊld ɡɹˈoʊθ ˌiːkənˈɑːmɪk dˌɛfɪnˈɪʃən ɪnðə fˈɔːɹɪst wʌz .
A 1993 Forest Service study estimated that the extent of old growth (economic definition) in the forest was .