I have two suggestions:
The California State RR Museum has some bound copies of employee timetables from the Southern Pacific. I have read some of the ones for the Salt Lake Division covering the Nevada & California era. These are available for reading; the library will not copy from these bound collections because of the size and weight.
CSRM library:
[www.csrmf.org]
The other is to read the local newspaper for the time period. The name change would probably be carried as a news item.
The Museum at Laws has original copies of the Inyo Register published at Bishop. The county library in Bishop has the paper on Microfilm. If you're in southern California the LA county Library in Rosemead has micofilms. Mircofilm of the Inyo Independent can be found at the county library in Independance, and also at Rosemead. In all cases, there may be gaps in the coverage.
also see:
California Newspaper Project
[www.cbsr.ucr.edu]
Brian Norden