The western part of the region consists of more broken and higher country, with a lower density of population, and is devoted largely to sheep farming. It extends from Kawhia and Raglan Harbours in the south (both are attractive to tourists) to the mouth of the Waikato in the north. Much of the area is underlain with rocks of the lower Tertiary Age, in contrast to the remainder of the region where Quaternary deposits are predominant. These Tertiary rocks are associated with the coal-bearing strata which gives rise to coalmining in the vicinity of Huntly. The coal is sub-bituminous and the reserves are not only the greatest in the North Island but also rank amongst the most important for the whole Dominion. In 1960,1,451,423 tons, representing 48·18 per cent of the national production, were produced in the Waikato. The mines are sited to the west of Huntly at Rotowaro, Pukemiro Junction, Renown, and Glen Afton, and are linked by rail to the Main Trunk. Mining is undertaken both by opencast and by underground means, and State and private companies are engaged in the enterprise. To the east of Huntly a large opencast mine exists at Kimihia. At Kopuku, mining of the Maramarua field was rapidly extended to coincide with the opening in 1958 of the thermal electric station at Meremere on the banks of the river to the south of Mercer. Its installed capacity is 180,000 kW. Further up the Waikato River, but within the limits of the region, are the first two hydro-electric stations constructed on the river, Arapuni (1929), with a capacity of 175,880 kW, and Karapiro (1947–48), with a capacity of 90,000 kW. The lake behind the dam at Karapiro formed an attractive setting for the rowing events in the 1950 Empire Games.