Built piecemeal in spurts by a succession of different companies, the Richmond Line was technically one the oldest in Portland. It began in 1888 as a horse-drawn rail line operated by the Willamette Bridge Railway Company. The line was electrified in 1890 and parts of the route were modified or moved around as the line was continually upgraded.*
The Richmond trolley's operated out the East Ankeny Carbarns until 1908, when they began operation out the Sellwood Car Barns after PRL&P Co. re-guaged them from narrow to standard.
Here we see Car 710 of the Richmond at the end of the line near S.E. 42nd and Clinton. The line sign on the car declares "WR" (Waverly-Richmond). Prior to 1900 they read "Waverly & Richmond." Thereafter they read "WS" (Woodstock), "RM" (Richmond), or "WW" (Waverly-Woodstock) in addition to "RW."
This poor bloke
just wants to
get where he's going.
This line toughed it out long after the diminishing of the trolley boom times. Service continued until September 27, 1936.
* This map over at the excellent Portland Vintage Trolley can help you trace the expansion and evolution of the line.