Coblion is found in route 13, terrakion in route 22 and virizion in route 11
Well, Cobalion pops up on route 13 and Verizion pops out route 11, and terrakion does so on route 22.
Cobalion is at route 13 at level 45. Virizion is at route 11 at level 45. Terrakion is at route 22 at again, level 45.