Reno is home to "Sun Valley," once listed in Guiness as the 'worlds' largest trailer park.' A typical mobile home will have the meter and main disconnect mounted on a pole. The PoCo will feed through a mast strapped to the pole, and the trailer will be fed from the disconnect.
This feed can be everything from a cord & plug (for the smallest trailers) to buried pipe. I'm not saying this is right; I'm just stating the way things are.
Despite the term "mobile," it is rare for these things to ever be moved once they're set up.
After a recent storm knocked down the service mast (nice fireworks there!), I was called to fix things. At that time, I also noticed the trailer feed was via SE cable, slightly buried, and too short in any event. This pic shows the exposed SE entering the trailer.
Please note that the outer PVC jacket has completely deteriorated from exposure to sun and weather:
It has since replaced with properly buried pipe, using flex for the last foot or two.