structural:summarization
Course

The distance of the river from its source to its confluence has been variously reported between 1,460 kilometres (910 mi) and 1,600 kilometres (990 mi). This uncertainty might result from the fact that the river flows through a series of virtually impenetrable gorges cut in the Ethiopian Highlands to a depth of some 1,500 metres (4,900 ft). According to materials published by the Central Statistical Agency, an Ethiopian government agency, the Blue Nile has a total length of 1,450 kilometres (900 mi), of which 800 kilometres (500 mi) are inside Ethiopia.