For the 1992 season the area around the Grand Canyon Rapids was recreated as Katanga Canyon with Gloomy Wood being built in a clearing beyond. Take a look at some of the plans and concept images produced ahead of the construction of the two areas.
Here we see one of the plans for the area and whilst it is pretty faithful to the what was built there a few differences. These mainly, involving the rerouting of the paths both at the entry to Katanga Canyon and at the entrance to what is today the Haunted Hollow. It also seems like there might have originally been more theming planned for the rapids.