Animas River

Along the Durango to Silverton narrow-gage excursion train, Colorado. The river's name is shortened from the Spanish original: El Río de las Animas Perdidas, "The River of Lost Souls." The story is that several members of a Spanish expedition in the 1700s were swept away and drowned while trying to cross the river.
Note the rust staining along the river banks. It's from acid-mine drainage, due to sulfide oxidation making sulfuric acid that in turn mobilized metals. Not all of it is a result of mining, but mining certainly exacerbated it! The stain is harmless--it's literally just rust (iron oxides and hydroxides), but it doesn't add to the esthetic experience--