USGS SIM 3480: Geologic Map of the Aeolis Dorsa Region, Mars
Approximately 5,000 kilometers to the west of Olympus Mons is the Aeolis Dorsa (Greek and Latin, respectively, for “Wind Ridge”) region of Mars. This geologically diverse area is around the size of the state of Arizona and has a complex depositional history. Much like on Earth, sediments on Mars were primarily deposited by wind, flowing water, or ice. One particularly interesting feature that hints at Mars’ watery past is the sinuous ridge, which is a winding, narrow ridge that looks like an inverted river channel. These ridges are interpreted to be aqueous (formed by water), making them possible clues about the history of water on Mars. Aeolis Dorsa is not lacking in sinuous ridges - in fact, it has hundreds of them to study.