A site in Tucson that contains footprints dating back more than two centuries will soon fall victim to the bulldozer.

The Arizona Daily Star reported Saturday that a worker excavating the planned site of a bridge over Interstate 10 discovered the footprints, which include both adult and child prints and even those of a domesticated dog. They're thought to be about 2,500 years old, which would make them among the oldest found in the American Southwest.

The archaeological excavation was being done in accordance with Pima County regulations for the project, which will connect Sunset Road to Silver Bell Road. But the discovery won't be enough to prevent new construction on the site.

If you'd like to see the site before it's gone, the county is hosting public tours Friday through Sunday the next two weekends: January 29-31 and February 5-7. Guided tours will begin every 30 minutes between 10 a.m. and 2 p.m. at the site, which is on the southwest corner of the intersection of I-10 and Sunset Road. A short walk over uneven terrain is required, and participants must wear closed-toed shoes and should bring sunscreen, a hat and water. For questions, call 520-724-6940.

A 3-D map of the site is also being prepared so its layout can be preserved even after it's paved over.

Editor's note: Our thanks to photographer Jonathan Bailey, whom we featured here a while back, for bringing this story to our attention.