E&P would be the Eureka & Palisades and its roster is not subject to much questions. However, it suffered from washouts and shut down in 1910 and for failure to pay an indebtedness it was foreclosed and sold at auction. The new owner of the railroad was the Eureka-Nevada, but for a while it was operated by the Nevada Transportation Company. The E-N's locomotive roster is part known and part unknown -- my favorite line is that trying to figure it out can drive one to drink. Part of the problem is that the general manager, John Sexton, seems to have been running a used ng railroad equipment business.
When the railroad started back up in 1912 after the washouts the new operators apparently wanted to use lighter weight locomotives and made a trade with the Sumpter Valley.
E&P #10 was a 2-8-0 built by BLW (s/n 11075) for Alberta Coal & Railway Co. in 1890 and acquired in 1910 just before the washouts. It reportedly was the locomotive caught in the washout and an engineman was killed. It became SV #15.
E&P #8 was an outside frame 2-8-0 built new by BLW for E&P in 1906 (s/n 28806). It became SV #14.
Other locomotives included in the trade from the E-N were one or two 4-4-0s.
In return the E-N received a light 4-4-0 (ex SV #15) and two 2-6-0s (SV #14 and SV #1/5). There probably was another locomotive as the E-N record books record that during the 1920s it wrote off a locomotive "left behind in Oregon."
Brian Norden