During this period, a series of marine fossil-bearing sediments known as Estratos de Lago Ranco were deposited in the lake area.

[7] According to a 2018 report from the General Directorate of Waters, in 2009, the lake had an oligotrophic level with a high degree of human intervention.

[8]: 27 One of the main tourist attractions in the area is Lake Ranco's beaches, featuring two commercial hubs: an artisanal fair, a food center, and a water park open to both locals and visitors during the summer months.

Many locals and outsiders, drawn by the area's beauty, proximity to major cities, reliable internet, and electricity, are starting businesses that can be managed remotely from Lago Ranco.

On 6 February 2024,[9] former President of Chile Sebastián Piñera died after the helicopter he was piloting crashed into the lake during a storm.