Thanks Dan for more info. I need to print your explanations for future reference. Smitty emailed me to explain blind siding from his SP&S perspective, which is as you say, one without an operator. I thought a siding always has a sw. at each end and a spur only one, but someone corrected me saying a siding can be with only one sw., so now I am confused. Are these terms not universal in at least the North American rr world? During the hay day of SVRy operation of the mainline, depots with an operator would have been Baker, S.Baker, Sumpter, Whitney, Tipton, Austin, and Prairie. As S.Baker was the company headquarter for SVRy, (OLC and Mt.Hood), and likely where the dispatcher was located, I am not sure that there was an actual depot agent at S.Baker though it is listed on tickets. As there was quite a community in S.Baker (a couple streets lined with houses that are just a large empty industrial lot today in addition to the area of town directly to the west of the S.Baker facilities) and it is over a mile to the Baker depot, I expect people would have boarded the train at S.Baker. Of the open depots, Prairie was closed first when the line from Bates west was abandoned in 1933, then Tipton in the mid30's and Sumpter not so long later. The rr built a small freight depot around the area where our S.Sumpter siding is to replace the actual Sumpter depot. I assume it was just an unmanned shelter depot like Salisbury, Lockhart, Thompson and White Pine. One can imagine a depot agent having been at McEwen in the early years when that was the end of the line.