The Marlborough region can be divided into three distinct parts: the back country, the plains, and the Sounds. The back country is composed of ranges, rising to their greatest elevation in the Inland Kaikouras (Tapuaenuku, 9,465 ft) and the Seaward Kaikouras (Manakau, 8,562 ft), which are largely tussock covered and extensively farmed in large sheep runs. The average area of holdings in Awatere county is 4,547 acres. The density of population is extremely low; Awatere county, 1·6 persons per square mile, cf., Marlborough county, 4·5, and the absolute numbers are negligible. The area is best considered as part of the South Island high country. Nevertheless, much of the original wealth of the district was founded upon these runs.
From the ranges the main rivers, the Wairau, Awatere, and Clarence, bring down their gravels and silt, and the largest expanse of plain that occurs in the region consists of the alluvial in-fill of the Wairau River. The Clarence is not responsible for any large alluvial plain. The remainder of the lowland area is found near the coast between Seddon (population 612, 1961) and Ward (population 218, 1961) and is associated with the alluvial deposits of the Awatere and rocks of the Quaternary period. In the southernmost part of the region a smaller area of Quaternary rocks projects out as a peninsula and is associated with a pocket of level land near Kaikoura. Obviously most of the region's population and economic activities are concentrated in these relatively small areas of plain.
Around Blenheim and Seddon mixed arable farming is the principal land use. Lambs are fattened and dairy cattle pastured, and cereals, peas, grass and clover seeds, vegetables, and flowers are cultivated. In 1960 a total of 16,452 acres in Marlborough and Awatere counties was devoted to the production of cereals and peas. Of this amount 4,592 acres were sown under peas and with this crop the region makes a significant contribution to the total New Zealand production. In addition, 5,849 acres of land were devoted to the production of wheat, and around Blenheim 351 acres were under vegetables for processing, 207 acres under potatoes, and 668 acres devoted to orchards and market gardens. The high number of sunshine hours, 2,400 hours at Blenheim, and the relatively low annual rainfall of 25·8 in. constitute favourable factors in the development of this type of farming. Sunshine and frequent strong drying winds provide suitable conditions for the production of salt by evaporation of sea water at Lake Grassmere, but varying weather conditions have brought annual production as low as 5,000 tons and as high as 20,000 tons. At Kaikoura dairying is somewhat more important, as is brought out by the figures for number of cows in milk per hundred sheep shorn, 1·81, and the fact that this small area contains 35·32 per cent of the dairy cows.
The third part of the region, the Sounds, derives its name from the drowned valleys which form a distinctive ria-like landscape that constitutes the main tourist attraction of the whole region. The Sounds have a higher rainfall (Picton averages 63·8 in. per annum) and were originally bush covered, being far less easily exploited than the tussock grasslands that were settled much earlier. Quite extensive tracts of bush remain in the Sounds and on the Bryant Range which separates the region from Nelson. Sheep farming is the main agricultural pursuit and some dairy farming is undertaken in the Rai Valley. The livestock figures for Sounds County show conspicuous downward trends; the number of cows in milk has fallen from 1,530 in 1921–22 to 222 in 1959–60 and, in the same period, the number of sheep shorn has declined from 190,712 to 134,116. And, with the exception of Picton Borough, the population of the Sounds area has revealed a similar downward trend. The heavy costs imposed by the difficulties of the terrain and the rapidity of second growth under the high rainfall conditions go a long way towards explaining the decline of the pastoral economy in the area.