Can you find the 13 hidden faces?

 
They Lived on this land and loved it
A thousand years before Columbus discovered it.
We call them Native Americans.
They call themselves The People.
They were scattered like leaves.
Where they walked softly, cities roar.
But their spirits remain.
We can never be alone.
Someone who loved this land watches over it.

See this link  for other example of hidden pictures within pictures.