Tony Koester's well-known HO scale Allegheny Midland layout is analyzed in detail in this fascinating new book. Built over the course of 25 years, the layout has been the subject of many Model Railroader magazine articles over the years. Here, Koester looks at lessons learned during the construction and operation of the Allegheny Midland. Using the author's original photography, he highlights many how-to lessons from its construction, along with the wisdom and perspective that comes from reviewing what worked and what didn't on one of the largest and most notable layouts in the country.