Northumberland role in the Industrial Revolution from the 18th century on. Many coal mines operated in Northumberland until the widespread closures in the 1970s and 1980s. Collieries operated at Ashington, Bedlington, Blyth, Choppington, Netherton, Ellington and Pegswood. The region's coalfields fuelled industrial expansion in other areas of Britain, and the need to transport the coal from the collieries to the Tyne led to the development of the first railways. Shipbuilding and armaments manufacture were other important industries before the deindustrialisation of the 1980s. Northumberland remains largely rural, and is the least-densely populated county in England. In recent years the county has
Trinity River (California) Less than 2 percent of the watershed is urbanized. About 86 percent of the Trinity River watershed is in Trinity County. As of the 2010 census, the population of Trinity County was 13,786. With a population density of 4.3 people per square mile (1.7/km) it is one of the least densely populated counties in California. Only , or about 14 percent of the western part of the basin, is in Humboldt County. The part of the Trinity River watershed in Humboldt County is also sparsely populated, with the exception of the Hoopa Valley Reservation, which was home to 2,930 people