The Itata river, which forms the southern boundary, and its principal tributary, the Nubee, form the drainage system of the province.
These are the Maipo (Maypo or Maipu), Rapel, Mataquito, Maule, Itata, Bio-Bio, Imperial, Tolten, Valdivia or Calle-Calle, Bueno and Maullin.
Some of the larger tributaries of these rivers, whose economic value has been equally great, are the Mapocho, which flows through Santiago and enters the Maipo from the north; the turbulent Cachapoal, which joins the Rapel from the north; the Claro, which waters an extensive part of the province of Talca and enters the Maule from the north; the Nuble, which rises in the higher Andes north of the peaks of Chillan and flows entirely across the province of Nuble to join the Itata on its western frontier; the Laja, which rises in a lake of the same name near the Argentine frontier in about lat.
A supply of rifles was bought in the United States, and embarked on board the " Itata," a Chilean vessel in the service of the rebels.
The United States authorities refused to allow this steamer to leave San Diego, and a guard was stationed on the ship. The " Itata," however, slipped away and made for the Chilean coast, carrying with her the representatives of the United States.
The " Itata " was then forced to return to San Diego without landing her cargo for the insurgents.