Northern Chilean Patagonia has numerous pristine lakes associated with perennial native forests. The present study looks at optical properties in visible, close, and medium infrared wavelengths in mountain lakes of Alerce Andino National Park (41°S). These lakes have associated Nothofagus and Fitzroya cupressoides native forests of glacial origins. The results revealed high reflectance values for B1 and B3 for Chaiquenes, Triangulo, and Sargazo lakes located within Nothofagus and F. cupressoides native forest; Precipicio Lagoon has high B3, B4, B5, B6, and B7 reflectance values, perhaps due to granite surroundings; and the remaining 18 lagoons have relative low reflectance values for all bands, probably due to the predominance of Cupressaceae forest and mountains that make access difficult. These differences are associated with surrounding vegetation and geological characteristics of the studied sites.