Plan of the River Oregan, from an actual survey.Broughton, William Robert, 1762-18211st. Novr. 1798.A detailed map of the Columbia River recording discoveries for about one hundred miles made by a member of George Vancouver's expedition in 1792. The account of the voyage on which the map is based can be found in Vancouver's A voyage of discovery to the North Pacific Ocean. London, 1798.cartographic