What is the etymology of the state name 'Oregon'?

The earliest evidence of the name Oregon has Spanish origins. The term "orejón" comes from the historical chronicle 'Relación de la Alta y Baja California' (1598) written by the new Spaniard Rodrigo Montezuma and made reference to the Columbia River when the Spanish explorers penetrated into the North American territory that became part of the Viceroyalty of New Spain.

This chronicle is the first topographical and linguistic source with respect to the place name Oregon. There are also two other sources with Spanish origins, such as the word oregano, referring to a plant which grows in the southern part of the region.

It is possible that the American territory was named by the Spaniards, as there is a stream in Spain called the "Arroyo del Oregón"; it is also possible that the "j" in the Spanish phrase "El Orejón" was later corrupted into a "g".

Most scholarship ascribes the earliest known use of the name "Oregon" to a 1765 petition by Major Robert Rogers to the Kingdom of Great Britain, seeking to finance an expedition in search of the Northwest Passage.

In 1766, Rogers commissioned Jonathan Carver to lead such an expedition and in 1778, Carver used Oregon to label the Great River of the West in his book 'Travels Through the Interior Parts of North America'.

The poet William Cullen Bryant took the name from Carver's book and used it in his poem 'Thanatopsis', published in 1817, to refer to the recent discoveries of the Lewis and Clark Expedition.