A worker excavating the planned site of a bridge and new interstate connection on the northwest side has unearthed a series of footprints, an archaeological find that is believed to date back more than 2,500 years.
The footprints stamped into the mud of an ancient irrigated field, dried solid and covered with sediment some 2,500 to 3,000 years ago.

While the entire area won’t be excavated, research could reveal seasonal variations in plantings, crop-rotation techniques and other irrigation schemes.

Source: The Archaeology News Network: Ancient footprints found at Tucson road construction site