In the middle part of the last century the idea of a Wanganui-Rangitikei region would have been more acceptable to geographers. For at that period Wanganui was the most important town and port for the whole of the south-western portion of the North Island. By its rail connections to the west and to the east it linked to the remainder of the colony and to the outside world a large proportion of the coastal lowlands, the lower Rangitikei, and part of the Manawatu. Furthermore, the Wanganui River provided access to the interior. The early settlement of the region was favoured by the relative ease with which the coastal scrub lands were brought into pastoral use, but extensive forests to the north delayed settlement, so that only at the turn of the century was the upper part of the Rangitikei and the Ohakune-Raetihi district finally settled, after the Main Trunk railway had been completed in 1908. Given this early start, Wanganui by 1878 was the eighth city of New Zealand. At the census of 1896, with a population of 5,936, it ranked seventh. By that time Palmerston North with 5,910 inhabitants had appeared as a strong competitor and the region of the lower Rangitikei and the northern part of the Manawatu, which had once been oriented towards Wanganui, now increasingly looked towards Palmerston North. Today the two cities are only an hour's drive apart, a factor which exerts a considerable influence on the future of Wanganui's development.

The growing influence of Palmerston North tends to enlarge the area included within the boundaries of the Manawatu; in creating regional boundaries economic influences override any similarities in physical geography. On this account the area drained by the upper reaches of the Pohangina, Oroua, Kiwitea, and the tributaries of the Rangitikei now look towards Palmerston North. In terms of physical geography, however, these areas have close affinities with the belt of hill country between the Rangitikei and Wanganui Rivers and for present purposes they have been included within the region. Contrasting with the hill country and forming the second major physical unit of the region are the broad sweep of coastal lowlands extending between Patea and Bulls. The small area around Raetihi and Ohakune requires special mention.