I think this was about the last semaphore signal in Nevada. We are on the Southern Pacific mainline near Deeth, NV on September 10, 1976. Note the train indicator on the top of the relay box for M/W crews. The semaphore signal gave a good indication of a train west of this signal, but since the track is for westbound trains, the signal was of little use to M/W crews unless trains were running against the current of traffic. The train indicator had a small semaphore signal to show if a train was in the next several blocks.

The following picture was taken from video at Albany, OR. The image is not quite as sharp, but it does show a standard SP indicator. There is a train approaching from the right so the right indicator is up. The block is clear to the left. These indicators were common across the SP system. However, like the semaphore signal, there are very few left today.

Semaphore Index

Yoncalla, OR