New River is an important tributary of the Trinity River. It rises in the Salmon Mountains in north-western Trinity County and flows in a southwesterly direction through the Denny area and eventually joins the Trinity River at Burnt Ranch. Gold was discovered here in 1849, and placer mining followed for some years. Lode mining began later, the chief producer having been the Mountain Boomer mine, which has a total output of more than $350,000. The area was prospected again in the 1930s. A number of gold-quartz veins occur in slate and greenstone. Other mines in the district include the Uncle Sam, Modoc, Sherwood, Mary Blaine, Hunter, Live Oak, and Gun Barrel mines.
Brown, G. C.; 1916, Trinity County, Modoc and Mountain Boomer mines: California Min. Bur. Rept. 14, p. 895. Min. and Sci. Press, Jan. 24, 1885, New River district, p. 53.