I love a good hunt and finding Lyon Switch was fun. I could find no reference on the Internet, using GNIS maps, my vast collection of Nevada resources. It was nowhere to be found.
So I looked at my 1930's map of Nevada (see map below on left) with all Nevada railroads and stations listed. 'Lyon' was on the map. Seeing that the word 'Switch' was usually associated with railroads, I decided to zero in on this location.
According to the map Lyon Switch was 5.6 miles from Fort Churchill. So the next step was to use Google Maps to find the approximate location of Lyon Switch (see map below on right).
This is definitely ranching territory and we know from the letter that they are talking about hay and sheep.
To help establish this as the area of Lyon Switch, I checked out "Qullici Ranch' on Google. Quilici is all over this area and Quilici Road is not too far from this area on Google maps (can you spot the intruder on the Google map?). The 1930 census confirms a very large number of Quilici's living in this area. So, I am pretty sure I have nailed down this spot!