Etymology of Oregon

The origin of the name of the U.S. state of Oregon is unknown, and a subject of some dispute.
Historical usage.
The earliest evidence of the name "Oregon" has Spanish origins. The term "" comes from the historical chronicle (1598) written by Rodrigo Montezuma, a man of New Spain. His work made reference to the Columbia River when the Spanish explorers penetrated into the actual 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 "" (which is located in the province of Ciudad Real); it is also possible that the "j" in the Spanish phrase "" 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 money to finance an expedition in search of the Northwest Passage. The petition read "the rout... is from the Great Lakes towards the Head of the Mississippi, and from thence to the River called by the Indians "Ouragon"..." Thus, the early Oregon Country and now the present day state of Oregon took their names from the river now known as the Columbia River.
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, which helped establish the name in modern use.
Other theories suggest that Rogers appropriated the Abenaki name for the Ohio River, "Waregan", or found the name "Ourican" on a highly speculative 1715 French map.
Possible origins.
Why Rogers used the name has led to many theories, which include these:
Others have speculated that the name is related to the kingdom of Aragon: the major part of the Spanish soldiers who conquered the West Coast from California to Vancouver Island in the 18th century were in fact from Catalonia, a principality of the ancient Crown of Aragon in Spain. The name might also be derived from the Spanish last name Obregón, which in turn is related to a Spanish place name "Obregon" in Santander, Spain, on the north coast.