The Río Limarí flows through the semi-arid Coquimbo Region of north-central Chile, draining a watershed that transitions from Andean headwaters down through a Mediterranean-climate valley before reaching the Pacific Ocean. The river system is shaped by a landscape of rolling hills, rocky terrain, and a riparian corridor that supports a surprisingly diverse assemblage of native freshwater fish. The Limarí basin sits within Chile's Mediterranean zone, a region characterized by seasonal rainfall patterns, warm dry summers, and cooler wet winters — all of which directly influence river flows, water temperatures, and fish behavior throughout the year. The watershed is notable from a biogeographic standpoint, representing one of the northernmost limits of distribution for several native Chilean fish species.