Because you wanted it, and because Mike Lee of Widen Your World graciously provided it, here's an interior layout of the beloved Columbia Harbour House complete with the original room names! I've been told that there were once small signs naming each room, which is possible, but I sure don't remember it.
What is included on this map which is of note, however, is the second floor kitchen which still exists, but has been walled in. Also, note that the divider between the Foyer and the Chesapeake Bay room was removed earlier this year to expand waiting space. Although it was a bottleneck, it was a charming bottleneck, and now it feels less like you're entering a real inn and more like you're inside a food court. Oh well.