University Indian Ruin (UIR), which sits in the eastern Tucson Basin, is a prime example of a Classic Period Hohokam platform mound archaeological site. The University of Arizona owns 13 acres of this site, and it is listed on the National Register of Historic Places using this acreage as its site boundary. However, multiple investigations have shown that the site is not fully contained within that boundary. This work seeks to answers to two questions about the UIR site. The first is to further investigate to duration of occupation at UIR, beyond the Classic Period. The second is to systematically investigate the extent of UIR into the surrounding residential community. Results include a new, proposed boundary for management by Pima County and the State of Arizona. How archaeologists define a site boundary is also investigated.