Back in August 2018 I wrote about how Doyle and Portola were in competition to become the division point for the Western Pacific. A reader recently questioned a comment that I stated the Western Pacific Railroad built the line, and wanted clarification that it should be the Western Pacific Railway—in their opinion two different companies.
In 1903 the Western Pacific Railway was incorporated to build a railroad from Salt Lake City, Utah to the San Francisco Bay. This was accomplished. The Western Pacific struggled financially, since it had no capital to build its proposed feeder lines that would increase freight traffic, thus increase revenue. In 1916, on the brink of financial collapse the Western Pacific Railway reorganized to become the Western Pacific Railroad—same company just a change in semantics. Now back to the original question, technically it was the Utah Construction Company that did the physical work to construct the railroad, under a contract with the Western Pacific Railway.