The Southern Pacific (SP) railroad in Utah is known for its unique crossing of the Great Salt Lake and its long history in the state: • History The SP entered Utah by leasing the Central Pacific's original line for 99 years at a yearly rent of $1.2 million. In 1903, the SP built a long railroad trestle across the north arm of the Great Salt Lake. This was one of the longest railroad trestles ever built at the time. • Merger In 1988, the SP merged with the Denver and Rio Grande Western to form the fifth largest rail system in the country.