High Quality Content by WIKIPEDIA articles! The Eagle Mountain Railroad (EMRR) was a private railroad in California, owned by the Kaiser Steel Corporation, and is owned today by Kaiser Steel`s successor, Kaiser Ventures, Inc. of Ontario, California. The EMRR is 51 miles (82 km) long and is located in Riverside County, California. Constructed in 1947-1948, it was used until 1986 to haul iron-ore from Kaiser`s Eagle Mountain Mine to an interchange with the Southern Pacific Transportation Company. The last revenue train to operate over the line was on March 24, 1986.