Left image: Satellite view of Great Bay, Mullica River, and Long Beach Island. Compare with center image of Mars. Center image: Context image (Viking) showing the region of the Hesperia crater paleolake and its tributary channel. Right image: The valley is 15-km wide at the level of the plateau and 4.5-km wide at the bottom, for an average depth of 1500 m, giving a slope of about 20 degrees.
Source: NASA, JPL, Malin Space Science Systems