After ranking the top 100 NHL prospects for 2015-16, and ranking each team by organizational depth, ESPN Insider Corey Pronman ranks the top 10 prospects for each NHL team. Here is his entry for the St. Louis Blues. Extended write-ups on prospects ranked in the top 100 can be accessed here.
The highlight of the Blues' system is a pair of high-end forwards. They have great depth on defense, though I wouldn't categorize any of the prospects as truly high-end at this point.