Jim,
I've played St. Charles dozens of times, it is unique in featuring 9 holes by Mackenzie & 9 holes by Ross which comprise the true 18-hole course at the 27 hole facility.
The Mackenzie nine is very good and much credit should go to Mike DeVries who completed some restorative work. The property is not overly inspiring, featuring very little elevation change with holes running predominantly back and forth in a north-south orientation. In spite of this the course is interesting owing to sound bunkering and well contoured greens. The two one-shotters are very good, one being a short, uphill pitch to a well-bunkered and steeply pitched green and the other being a long iron to a green divided into a high left and low right sides, making for some interesting and nervy recovery shots. The par 4's are very good and the reward for well-placed drives is in existence, but improved mowing lines would enhance the strategy of the design. The par 5's are both good, but not spectacular.
The green recapturing and bunker work by DeVries is very good and adds nice detail to the course, sadly I don't think he ever got to totally complete the work. The golf course is not 100% Mackenzie. In a successful attempt to land the Senior PGA Tour, the club demolished the 3rd green to accommodate a new back tee on 7. A drivable par four was replaced by a similarly short but severely doglegged hole that doesn't fit in with the rest of the holes. Ironically, the tour did not play from that back tee during the tournament!! The 5th and possibly the 9th green were rebuilt in their original location, with the former seeming to have lost much of its original character.
St. Charles is a wonderful facility and always in very good condition. While I lament some of the architectural changes over the years, I always look forward to an upcoming round.
Tyler