The SS Beaver was a passenger-steamer for the Union Pacific Railroad,
Launched in November 1909. It was acquired by the Navy, in July 1917 and converted to a Submarine Tender at Mare Island Navy Yard, Vallejo, CA. She was Decommissioned, struck from the Naval Register, and transferred to the War Shipping Administration for disposal in 1946. The Boston Metals Corp scrapped in the ship 1952.
I became aware of it through an early 20th century postcard featuring the sleek, low-slung vessel, sent to Mrs. Jessie Fee, Auburn, Indiana with a one cent green Washington stamp:
“San Francisco, Cal 2/9 1913
A fellow from Minn. came here with me, we were thirty hours on the Ocean we came on the Beaver, we left Redondo Friday noon. Frisco is some town. Pops.”