sentences:  On the upper reaches of the river in the mid-1960s rich deposits of precious stones, including sapphires and spessartine, were discovered.Also on the river is the Umba River Game Reserve, a wildlife reserve that includes along with the Mkomazi Game Reserve, about 2,600 km².The flow of the river has been observed over 40 years (1963-2003) in Mbuta, a town about 40 km above the mouth.