Historical Features are physical or cultural features that are no longer visible on the landscape. Examples: a dried up lake, a destroyed building, a hill leveled by mining. The term makes no reference to the age, use, or any other aspect of the feature. A ghost town, for example, is not a historical feature if it is still visible.
Channel - Linear deep part of a body of water through which the main volume of water flows and is frequently
used as a route for watercraft (passage, reach, strait, thoroughfare, throughfare).
Not a Stream or Valley.