Here is my idea which is a blend of all of the good ideas we’ve had so far. This is the simplest approach I can think of that will be extremely effective.
The model base would be made of MDF board (same material Ernie used for his LA 103 model) at 2′ 6″ wide for a seamless and sturdy sleeve for the laser cut “ribs” (cardboard or basswood) to slide in. This will create a unity to the piece and make the river feel as if it has a base holding it up.
The model will be suspended from the ceiling and held up by these pieces of wood that I can get very easily from the home depot. They are used to hold lumber off the ground so the forks of a forklift can fit under, they already have the grooves cut out to hold hanging line in place.
Depending on the amount of detail we intend to have on the top of the model itself, I don’t think we need to create any kind of step for people to see higher parts of the river, by standing adjacent and back a little, one will still be able to view these parts of the river.
Also, disregard diagonal lines running across model base.