The river is believed to have been an ancient channel of the Colorado, as well as the primary outflow for the prehistoric Lake Cahuilla.

The watershed of the Hardy River includes runoff from the eastern foothills of Sierra de Los Cucapah to the west and the southern slope of Cerro Prieto.

The Rio Hardy is home to a variety of wildlife, including the mosquitofish and the sailfin molly[1] The Hardy's wetlands are a nesting ground for the snowy egrets (Egretta thula), and with the bird habitat, are part of a protected Mexican biosphere reserve, the Reserva de la Biosfera del Alto Golfo de California y Delta del Rio Colorado.

[2] In recent years, the Hardy has become a drain for agricultural waters polluted with pesticides and fertilizers from the Mexicali Valley.

[3] The water quality in the Hardy is being monitored at Mexicali by the Centro de Investigacion en Alimentacion y Desarrollo A.C. (Food and Development Research Center) to measure the effects of discharge from the Las Arenitas wastewater treatment plant.