Here is the entire question -- I can't seem to display the entire environment model in my viewer when I dolly the camera out. If I'm close in, I can see the model fill the viewer. But as I move away, the model appears to start being cut with a vertical plane and I see the default blue sky background instead. How can I make my entire model/drawing display in the viewer as I dolly out?

What is happening is simply that the default camera settings have near and far clipping planes which help large complex models to be displayed efficiently on your computer. These clipping planes tell the viewer the distance range for objects that can be displayed. By default, objects closer than 2 feet or farther than 2000 feet from the camera will not be displayed. A quick way to override the default settings so that it will show the complete model is to place your mouse cursor over the scene and right-click. In the menu that appears, choose Preferences and then check Auto clip planes. Now when you dolly out, you will always see your environment drawing/model displayed in the viewer.