Much of the original equipment came from the Utah & Northern Railway in Idaho and Montana. The Union Pacific owned the line and began converting it to standard gauge around 1887. Eccles owned a significant amount of Union Pacific stock, exerting enough influence to acquire the now-unneeded narrow gauge equipment. The first locomotive to arrive was a small 4-4-0 numbered 285; the Sumpter Valley also purchased a number of the U&N's Brooks 2-6-0 locomotives, along with a large number of boxcars and flatcars. In 1906, the railroad also acquired four locomotives from the Tonopah Railway (later the Tonopah & Goldfield Railroad).