All of the Atlanta stations appear to be diffracting over the tops of the mountains (everything is showing "2edge") in order to reach you. Even though the stations are only about 40 miles away, the signal strengths are not that strong due to terrain blockage. However, most of the stations are still coming through with enough signal power to be received reliably.
Here's a cross-section view of the terrain between WGTV and your location (you can click on the table in your report to get this for any of the channels):
You will want a "big" antenna (like the Winegard HD7698P or Antennacraft HBU-55) plus a good pre-amp (like the Channel Master 7777, Winegard AP-8275, or Antennacraft 10G202) to get the maximum number of channels with the greatest reliability. All you need to do is aim the antenna at Atlanta (around compass heading 273ยบ) and you should be able to pick up most of the network stations.