To me, a dark horse would NOT be in the top 30 now, so they wouldn't be on this list (http://www.ustfccca.org/2014/09/featured/division-i-cross-country-national-coaches-polls-remain-calm-but-not-for-much-longer).
AND, they should NOT be a top 3 on the regional list (http://www.ustfccca.org/2014/09/featured/regional-rankings-in-division-i-xc-hold-steady-ahead-of-a-big-weekend-of-races?doing_wp_cron=1411405403.1416220664978027343750).
Interestingly, the only schools that are top 3 in region but not top 30 national are: Auburn and Florida (from South region), Texas A&M (South Central), i think.
The 'chalk' pick would probably be Columbia or G'town. But, I'm going to go very, very dark and pick...Notre Dame!