By Laurel Morales
http://stream.publicbroadcasting.net/production/mp3/knau/local-knau-939114.mp3
Flagstaff, AZ – Grand Canyon Superintendent Steve Martin has announced plans to retire. He's led the park for almost five years and has faced some challenging issues such as uranium mining near the park, Colorado River high flow experiments and over flight noise. From the Changing America Desk Laurel Morales spoke with Superintendent Martin about some of those challenges.