The Hardy River (Spanish: Río Hardy) is a 26-kilometer (16 mi)-long Mexican river formed by residual agricultural waters from the Mexicali Valley and running into the Colorado River. The river is believed to have been an ancient channel of the Colorado.In the 19th century, a sea captain (Captain Hardy) explored the Colorado River Delta, and noted that the main channel of the Colorado followed this course. Later in the 1880s, sea captains noted that the main channel of the Colorado had moved east, and this old channel became known as Hardy's Colorado.