Simeon R. Buford was born on a farm in Lewis County, Missouri, on March 2, 1846. He was the third of fifteen children of Wellington and Amanda (Staples) Buford. In 1865 he drove an ox team across the plains to Virginia City, Montana Territory. He established a freighting business driving ox teams between Virginia City and Fort Benton. With the completion of the Union Pacific Railroad he shifted his freight business to the profitable Virginia City to Corinne, Utah, route. In 1872 he began working as a clerk in the Raymond Brothers store. Using experience gained in this job, he opened his own store in 1878 in partnership with Henry Elling. S.R. Buford and Company became the largest store in Virginia City, gradually expanding its trade from wholesale groceries and liquor to general merchandise. Buford and Elling were close personal friends and became partners in other enterprises as well as the store. Buford was one of the founders of the Elling State Bank and served as its president after the death of Henry Elling in November 1900. The two men also operated a hardware store under the name Elling, Knight and Buford and were partners in a stage line, a horse and cattle ranch in Custer County, and hay and sheep ranches at Valley Garden and the #9 Ranch in Madison County.

During the Nez Perce War of 1878, Buford served under General Howard at the Battle of Camas Creek. In politics, Simeon Buford was an active Democrat. He was a member of the 1889 Constitutional Convention and served in the 1891 and 1893 Legislatures. In the Senate he promoted the location of the State Orphanage at Twin Bridges. For fourteen years he headed the Madison County Democratic Central Committee. Simeon Buford was also active in several fraternal orders, including the Benevolent and Protective Order of Elks, the Independent Order of Odd Fellows, and the Ancient Order of United Workmen.

Simeon R. Buford's younger brother Charles H. Buford (1860-1926) assisted his brother in his freighting business and had a livery stable in Virginia City. He took over the mercantile business, under the name Buford Mercantile Company, on the death of his brother.

On January 4, 1877, Buford married Kate Cooley, daughter of William A. Cooley. The couple had eight children of whom four survived to adulthood: Henry W., Effie, Simeon R. Jr., and Ruth. Simeon R. Buford died January 15, 1905.

Henry W. Buford, (b.1878) oldest son of Simeon R. Buford, was an active participant in his father's business helping to run the store and managing the Valley Garden Ranch.