I think it was said earlier - but it would have been interesting to see this list 10 years ago, 20 years ago, and who would have been included then and who isn't now. Two "smaller" schools from Michiana that I personally have always viewed as "blue blood" programs that I don't think have been mentioned yet are Jimtown and NorthWood.
The Jimmies have 22 Sectional, 12 Regional, 6 Semi-State and 4 State Championships. However, the last of each of those titles respectively are 2014, 2009, 2005 and 2005. Since the school has grown into a 3A enrollment, they have not seen the same level of postseason success that they did for the better part of 3 decades.
The Panthers have 18 Sectional, 11 Regional, 6 Semi-State and 1 State Championships. As the case is with the Jimmies, since they moved into class 4A a little over a decade ago, they won a Sectional Championship in 2011 and were State Runner-Ups (14-1 record) in 2016. It has been tougher sledding for NorthWood since moving to 4A.
I still consider both of these programs to be "blue blood" status. However, that is just my opinion.