For example , Unit VI appears to have been transected by a tractor since the 1960s when Patterson first reported it as a complete structure .
There has been some uncertainty over the number of buildings on the site , primarily due to recent surface disturbance .
Unit VI appears to have been transected by a tractor since the 1960s when Patterson first reported it as a complete structure .
There has been some uncertainty over the number of buildings on the site , primarily due to recent surface disturbance .