Many locomotives are stored in Northtown in this picture but luckily this isn't the case anymore. As of a couple days ago, All the SD75's were gone, reactivated and in service. Only a few older Geeps and a lone SD9 were remaining.
There are times when many engines, cars or cabooses are concentrated in a location. Such sites are for storage, economic reasons, active power needs or for rebuilding. For others, wear and tear have brought their usefulness to and end.