The Baker River discharges into Martinez Inlet, the northern part of this large estuary.
[1] It penetrates the mainland about 75 miles (121 km) and opens into Tarn Bay at the south-east corner of the Gulf of Penas.
[1] Baker Channel also receives the waters of the O'Higgins/San Martín Lake through the Pascua River.
The shores of the channel contain forests of Nothofagus nitida and Pilgerodendron uviferum.
[2] These forests are rich in lichens endemic to Chile and nearby areas of Argentina.