I now live in Lake County, CA. Born in 1949. I grew up in Belmont California, and on the San Francisco peninsula during the seventies, and eighties so the Southern Pacific was what I saw most of.
I remember the SP yard in South San Francisco with its round house, and lots of steam and early diesel. As well as the third street yard in San Francisco.
By the time I moved in to San Francisco from the Peninsula in 1985 it was all diesel. My model railroading era is around late 1994-1998, in the west of Texas. Includes, produce, petroleum, industrial, lumber, and yard switching then running to and from staging.
Watching the SP switchers and GP's move cars down from the 3rd st yard and down Howard St from out my front window set me as a convert. So I tend to like modeling this type of railroading.
I only know about the railroad business from what I have read. Mostly, wonderful info from those who do do it for a living. Track level operations is where it is at.
I look at my current layout as a advanced learning experience (the first real try in DC, 1975 is best forgotten). I did learn that I preferred N over HO or the O-27 and American Flyer S scale I had.
DCC and the ability to have remote radio throttles got me hooked again.
I now use a Digitrax Super Empire Builder with DT400R and UT4R radio throttles.