accommodated development from 1975 to about 1985 (Portland, Oregon), when the IGB was effectively removed and development could extend out to the UGB. Consequently, IGBs are used to prevent the premature development of land located near the UGB before land inside the IGB is first suitably developed. Case/Example: 1976-1985, Portland (OR). Source/Reference: Nelson and Duncan, 1995, pp. 81.