I was asked how to recognize the houses. Here is a little more information on navigating the Topo Map. The homes are the little black squares. You can also zoom in even closer by using the zoom tab. Go to a known area and you will be able to more understand what you are looking at. Some times a mine will appear as a crossed pick and shovel emblem. Also, over the right screen you will see small, medium and large. Click on large and this will give you a full screen image. You will then have to use your vertical and horizontal scroll bars to navigate the entire screen. Click on the little arrows at the edges and corners and you can navigate in that direction to the adjoining area. Click anywhere on the screen and where your cursor is pointing and that location will go center screen. You can actually drive all the way by Highway 50 from California to New Jersey in this manner but you will need several lunches on the way. Robert