Online Aerial Photography
The State of Oregon maintains several web sites that can be used to access Aerial Photography of Oregon.
EarthExplorer is a good place to look for individual aerial photography frames of anywhere in the United States. You can search and download images from a number of USGS aerial photography programs. Elevation data, Landsat data, and other satellite and remote sensing data is also available. Aerial photography in EarthExplorer includes:
The Knight Library Aerial Photography Collection has 1,000,000 unique images, primarily paper prints but also original film and digital photographs. Our earliest images are from 1929. The majority of the photographs were taken in the 1930s up to the 2000s. They cover all of Oregon and some surrounding states, especially western Washington. Many of these physical images are irreplaceable and some are in fragile condition which is why the Library mediates access to the physical materials.
Check with your class instructor. They may have already requested an aerial photography time series of the area your class is studying and provided access to them via Canvas.
If you wish additional aerial photography for your classwork, contact the Aerial Photography Research service.