For those in the Portland area and in particular Hillsboro, there is a new Arcadia Pub. book out: "Railroads of Hillsboro." Includes a chapter on contemporary operations as well... Here is the synopsis from the publisher's website:
Hillsboro, Oregon, always seemed destined to be an important railroad town. When the first trains arrived in Hillsboro in 1871 under the banner of the Oregon & California Railroad, the town began to develop into a key railroad junction point. Hillsboro was strategically located just 20 miles from the booming Portland metropolis, a regional center of manufacturing and trade, and by 1911, Hillsboro was where several rail lines branched off. One line headed west toward Tillamook, where the railroad tapped rich timber resources along the Oregon coast. Another line cut south into the fertile Willamette Valley, accessing prime agricultural lands that produced a bounty of wheat and other commodities. A third route carried passengers and goods to and from Portland and the neighboring communities of Cornelius and Forest Grove. As these routes developed, heavy volumes of freight began rolling into Hillsboro. At the same time, travelers moved through Hillsboro on passenger trains, including the Southern Pacific Railroad's famed "Red Electrics" and the Oregon Electric Railway's interurbans, which advertised passenger service with "no soot and no cinders."