Black fly larvae need clean, flowing water to develop
because they are attached to solid surfaces, like
rocks, and feed by filtering the water that flows
Scotty's Castle is located near natural springs which
support dense vegetation (see vegetation in the
background of photo above) in this otherwise barren
landscape. These springs were tapped to provide water
for the home. So much water is available that some
landscape features sport permanent flowing water,
which supports a vibrant black fly population!
So that's the answer to another mystery
of Death Valley and some insight into black
fly biology. Black flies need flowing water but not a
river. Even a fairly small trickle will do as long as
the water is clean.