The lake was formed by the retreat of the San Rafael Glacier in the Northern Patagonian Ice Field. Today it is a popular tourism destination, and ships sail from Puerto Chacabuco, Puyuhuapi and Puerto Montt to the lagoon nearly every day to see the ice falling from the glacier into the lagoon. Cruises pass by this area.
The lake was visited by the Antonio de Vea expedition in December 1675. The expedition entered San Rafael Lake taking note of its windy conditions, the San Rafael Glacier and the swampy shores in the south that make up the Isthmus of Ofqui.[1] Antonio de Vea entered San Rafael Lake through Río Témpanos (Spanish for "Ice Floe River") without mentioning any ice floe but stating that the San Rafael Glacier did not reach far into the lake. This has been interpreted to reflect that the effects of the Little Ice Age were not yet to be seen in the lake the late 17th century.[2]
^Araneda, Alberto; Torrejón, Fernando; Aguayo, Mauricio; Torres, Laura; Cruces, Fabiola; Cisternas, Marco; Urrutia, Roberto (2007). "Historical records of San Rafael glacier advances (North Patagonian Icefield): Another clue to 'Little Ice Age' timing in southern Chile?". The Holocene. 17 (7): 987. Bibcode:2007Holoc..17..987A. doi:10.1177/0959683607082414. hdl:10533/178477. S2CID128826804.
