This dataset presents 28 georeferenced orthomosaic images of the middle and lower reaches of the Elwha River. Each mosaic image was created by stitching together thousands of individual photographs that were matched based on numerous unique tie points shared by the photographs. The individual photographs were taken by a plane-mounted camera during multiple flights over the study area spanning 2012 to 2017. Because each mosaic is orthogonal to the earth's surface and is georeferenced to real-world coordinates, changes to the river channel and surrounding morphology can be seen and measured, including channel width, river braiding, bar formation, and other metrics to assess responses of the river to the removal of two large dams upstream from the study area.