BIO-BIO RIVER

river in south-central Chile. It rises in the Andes on Chile's eastern border and flows generally northwestward to enter the Gulf of Arauco on the Pacific Ocean near Concepcin after a course of 240 miles (380 km). The Bo-Bo River traverses the fertile Central Valley and then forms the only major transverse valley through the coastal mountain range. Although it is one of Chile's longest rivers, it is navigable only by flat-bottomed boats. The Bo-Bo is commonly referred to as the southern limit of middle Chile, where about three-fourths of the nation's people live.