This district is located in western Nevada and eastern Yuba Counties 20 miles east of Marysville and 15 miles west of Grass Valley. It includes the Mooney Flat, Sicard Flat and Timbuctoo areas. It is mainly a placer-mining district.
The streams were placer-mined during the gold rush. The town was named for James Smart, who built a hotel there in 1856. The area was extensively hydraulicked from around 1855 to 1877. Some drift mining also was done during these years and continued through the early 1900s, but little work has been done here since. The value of the total output of the district is unknown. In 1877, it was reported to have been $13 million.
The main channel of the Tertiary Yuba River enters the area from the north and goes through Mooney Flat. It then curves west and northwest through Smartsville and Timbuctoo and then west to Sicard Flat. The gravel deposits arc extensive and up to 200 feet thick. The lowest "blue" gravel on bedrock was the richest. The average yield during the major early operations was 37 cents in gold per yard, but some drifting yielded up to $3 per yard at the old price of gold. It has been estimated that 46.5 million yards were removed prior to 1891. Bedrock is greenstone, and in places the gravel is overlain by andesite.
Hobson, J.B., and Wiltsee, E.A., 1893, Smartsville mining district: California Min. Bur. Rept. 11, pp. 314-316.
Lindgren, Waldemar, 1895, Smartsville folio: U.S. Geol. Survey Geol. Atlas of the U.S., folio 18, 6 pp.
Lindgren, Waldemar, 1911, Tertiary gravels of the Sierra Nevada: U.S. Geol. Survey Prof. Poper 73, pp. 121-130.