The Colorado River's name is Spanish for the "color red" referring to the river's muddy color, but Colorado was just the final in the long line of labels this iconic river has worn over the years. Originally the 16th century Spaniard explorers called the river Rio del Tizon, which translated to mean River of Embers or Firebrand River and supposedly described a practice local natives used to warm themselves. Later, some maps named the river the Rio Colorado de los Martyrs and the El Rio de Cosminas de Rafael, again names that indicate the characteristic red of the water coupled with reference to martyrs and Rafael, perhaps Saint Rafael, but the specifics of these names are unknown.
The upper stretches of the Colorado from its headwaters near Estes Park, Colorado in the Rocky Mountains down to the junction with the Green River in Utah was known as the Grand River until as late as 1921, when a Colorado senator petitioned for a formal change to Colorado. As far as the rest of the river, it is unclear when exactly the name Colorado stuck once and for all. Jedediah Smith first reached the lower stretches of the river in 1826. At that time, he called it the Seedskeedee, as the trappers knew the Green River, one of the Colorado's primary tributaries, but he also noted that the natives in the area called the river the Colorado. By the time, John Wesley Powell navigated and mapped the canyon, Colorado was the accepted name and its other monikers long forgotten.