Silas Sanford Smith (October 26, 1830 – October 11, 1910) was a Mormon pioneer, a politician in the Utah Territory, and the leader of the San Juan Expedition that settled San Juan County, Utah. Smith was born in Stockholm, New York. His father, Silas Sr., was a younger brother of Joseph Smith Sr., which made Silas Jr. and Joseph Smith Jr. first cousins. Silas Sr. was baptized into Smith's Church of the Latter Day Saints in 1835 and the family became followers of Smith. After Silas Sr.'s baptism, the family moved to Kirtland, Ohio. A few years later they joined the Mormon settlers in Missouri and in 1839 they were driven out and settled in Nauvoo, Illinois. In 1847, after Joseph Smith was killed, the family left Nauvoo and crossed the American plains as Mormon pioneers, settling in the Salt