Several years ago, the American School’s long-running series on the Corinth excavations was released via JSTOR allowing anyone with access to JSTOR to browse thousands of digitized pages of archaeological volumes from Corinth. I have been hoping that digitized works of the Isthmia series might someday be released via JSTOR as well. I don’t know of what plans are in place for that end, but I did see that Joseph Rife’s monumental work on skeletal material from the sanctuary is now available for digital consumption. To download or browse the digital edition, you will need access to JSTOR, of course. Here’s the link.
Two more volumes of the Isthmia series are accessible openly. Got to http://ancientworldonline.blogspot.com/2009/10/open-access-publications-publications.html and scroll down