Public Affairs This Green Earth - April 30, 2019 John Ross KPCW | By Chris Cherniak, Nell Larson Published April 30, 2019 at 11:12 AM MDT Facebook Twitter LinkedIn Email Listen • 24:47 In the second half of the program, author John Ross talks about his new book, The Promise of the Grand Canyon: John Wesley Powell’s Perilous Journey and His Vision for the American West.