Flowing through the southern Buenos Aires Province of Argentina, the Río Sauce Grande is a prairie river system characteristic of the Pampas region. It winds through a landscape of rolling grasslands and agricultural terrain before eventually draining toward the Atlantic coast near the city of Monte Hermoso. The river passes through or near several notable towns, including Tornquist and Bahía Blanca, and traverses a variety of habitats that support a diverse assemblage of native freshwater fish. As a lowland prairie stream, the Río Sauce Grande exhibits the typical characteristics of Pampean river systems — relatively shallow and meandering, with stretches of slow to moderate current, muddy or sandy substrates, and riparian corridors of native grasses and gallery vegetation.