Ecology of a City Park Report The following images and text have been excerpted from: The Ecology of a City Park: Frick Park, Pittsburgh, PA by William LeRoy Black, M.S., University of Pittsburgh, 1947 This report can be found at the University of Pittsburgh's Hillman Library   Dust blowing from the slag fill in Nine Mile Run Hollow    Fern Hollow Creek disappearing under the Storm Sewer  A View of Nine Mile Run looking upstream in Nine Mile Run Hollow     Sewage flowing into Nine Mile Run from the Main Sewer    Area 2 in Fern Hollow with smog hanging over Nine Mile Run Hollow  Area 3 in Fern Hollow looking upstream into the Picnic Area