This Web site uses frames.
You may find that when you click on a new URL, you will be looking at the new page inside the old frame. If this is annoying, particularly when you're trying to view a full-size page within a relatively small frame, right-click the URL, choose Open Link in New Browser Window and you will leave these wretched frames behind.
Just hit the Back Button on your browser to return to the Pony Express Home Station.
If you want to create a bookmark, also open the page in a New Browser Window.