Colorado

The demonym 'Coloradan' stems directly from the Spanish word 'colorado,' meaning 'colored red,' 'reddish,' or 'ruddy.' The name originally referred to the Colorado River, which Spanish explorers in the 16th and 17th centuries named 'Río Colorado' due to the distinctive red-brown color of its silt-laden waters, particularly visible where the river cuts through the red sandstone formations of the region.

Early Spanish documents from the 1700s show various forms: 'Río Colorado,' 'Río Rojo' (Red River), and 'Red River of the West' to distinguish it from other Red Rivers. The Colorado River's characteristic color comes from massive amounts of suspended sediment—primarily iron oxide-rich red clay and silt—carried from the erosion of red rock formations including the famous redrock canyons and mesas throughout the Colorado Plateau.

When American trappers, traders, and explorers began arriving in the early 1800s, they adopted the Spanish name, anglicizing it to 'Colorado.' The region was variously part of Spanish Nuevo México, then Mexican territory after 1821, and came under U.S. control through the Treaty of Guadalupe Hidalgo (1848) and subsequent agreements.

The Territory of Colorado was organized on February 28, 1861, during the early days of the Civil War. Alternative names proposed included 'Jefferson,' 'Lula,' 'Idaho,' and 'Yampa,' but 'Colorado' was selected to honor the great river that provided life to the region. When Colorado achieved statehood on August 1, 1876—exactly 100 years after the Declaration of Independence—it earned the nickname 'the Centennial State.'

The demonym 'Coloradan' uses the suffix '-an,' though historically both 'Coloradan' and 'Coloradoan' have been used. By the late 19th century, 'Coloradan' became the preferred and more widely accepted form, following the pattern of similar state demonyms.