If you are on the Yahoo!Group for the ACSian class of '66/'68, there are enough clues to make contact, otherwise you can mail to that group email. If you are from the ACSian class of '66/'68 and not in the Yahoo!Group then you need to contact somebody from there whom you know in the network, or add a comment to one of the entries in the blog.
If all this sounds inconvenient, and it seems silly not to provide email addresses on the blog, there is a very good reason. Any time an email address is published on a public website or a blog, it can be collected by web crawlers (sometimes aka spiders) and sold to spammers who then proceed to email you about body enhancement products, performance enhancement products, making $1m from $5 in 3 weeks, Russian mail-order brides, and other things which you may or may not be interested in. That is also the reason the Yahoo!Group itself is closed, so its existence is not announced on the web, membership is by invitation only, and only members are allowed to post to it.