Natural World: Animals, plants and landscapes; geological or climatological features; and scientific processes and endeavors.
Travel: Locales, peoples or activities in the United States and abroad that convey a sense of place.
People: Portraits and photos of groups or individuals.
The American Experience: Events, objects or activities connecting the American people to their history or their cultural heritage; photographs that tell us what it means to be an American and provide a sense of what it is like to live in this country.
Altered Images: Photographs manipulated for artistic purposes by applying digital and/or traditional special effects (i.e., colorizing, toning, collage, photo composites, HDR, etc.).
Mobile: Any photograph taken with a mobile device (phone or tablet).
You may submit no more than 15 photographs per category for a contest total of 90 submissions. Online submission of digital photographs via the website.

Image requirements: jpeg, .jpg or .gif format, edited for web, at least 2,000 pixels wide and no larger than 10 MB. Finalists will be asked to submit an original, unedited digital file or an original negative, print or slide.

Judging criteria: creativity, quality, originality, responsiveness to the prompt and overall impact.