The lake is formed by the flow of the Desaguadero River at its mouth into Lake Poopó, over the extensive sedimentation known as "Santo Tomás" from the small hermitage found there that was completely inundated. The formation dates to 1962. The river connects Lake Titicaca and Lake Poopó.
The lake is a tourist attraction for boating and fishing, as it contains a large number of fish.
Oruro is located very near the shore, and is an industrial mining center.