Pellegrini Lake, lake in Argentina

Pellegrini Lake is an artificial reservoir in the Cuenca Vidal, a natural depression in Río Negro Province near Cinco Saltos. It was filled by a derivation channel from the Neuquén River after the Dique Ingeniero Ballester began diverting irrigation water in 1915. The lake covers 112 km², with a mean depth of 9.4 m and a maximum of 18 m, and its slightly saline endorheic waters are used for fishing, water sports and birdwatching.

The lake formed when water from the Neuquen River was channeled into a natural depression, creating a large reservoir to serve irrigation needs for the Alto Valle region. This infrastructure later transformed the area into a recreation destination, opening it to tourism and community use.

The lake's name comes from the Pellegrini family, and its shores host the Fiesta Provincial del Agua every February. On 21 September the Fiesta del Estudiante y la Primavera draws crowds to the peninsula Ruca Có, the tourist village where water sports and birdwatching are concentrated.

The lake lies 14 km off National Route 151, the road to and from Argentine Patagonia, near Cinco Saltos. Its level is managed for the Alto Valle irrigation system and varies by about 0.30 cm with the season. The Ruca Có peninsula, above the 274 m mark, holds the residential and tourist area.

The lake's environmental conditions make it a notable habitat for birds, and areas have been set aside for birdwatching as a complementary recreational offer. The lake lies in the endorheic Cuenca Vidal depression, a basin with no natural outflow, which is why its water is slightly saline.