The SP Tucson Hospital didn't make it long enough to part of the UP. Some basic details from a story about Tucson passenger stations in the Tucson Weekly (http://www.tucsonweekly.com/tucson/the-other-station/Content?oid=1872213) a few years ago:

"In 1929, Southern Pacific announced it was going to erect a tubercular sanatorium for its employees near the former (EP&SW) station. Headed by Dr. Charles A. Thomas and S.C. Davis, the hospital opened in 1931. Among its 100-beds and other facilities was a separate "Negro ward" for the company's black workers. The hospital served railroad patients with tuberculosis until 1946, when it became a general hospital for Southern Pacific employees. In 1964, it was opened to the entire Tucson community, and three years later, it was named after longtime U.S. Sen. Carl Hayden. It was closed permanently in 1974 and demolished five years later."

The area is now a parking lot and near a federal court house, among other downtown buildings.

A relative was an engineer out of Tucson, and I still hear stories from his children about visiting the Spanish-style hospital downtown with red tile roofs and lots of green grass.