This week we take the show to the archeological site at I-10 and Sunset Road. During the prep work for a road project, the county found irrigation, farms and human footprints dating 2,500 to 3,000 years old. We ask what we can learn from this evidence of ancient Tucsonans. Guests: Ian Milliken, archeologist, Pima County Dan Arnit, owner, Innovative Excavating Inc. Roundtable: Zac Zielger, Arizona Public Media Patrick McNamara, Arizona Daily Star Linda Valdez, Arizona Republic