The Klamath River flows across the northern portion of the Klamath Mountain province. It enters the Klamath Mountains in the vicinity of Hornbrook, flowing southwest and then generally west for more than 50 miles, crossing a number of well-known mining districts. The placer-gold production has come from the present channel and a succession of terraces and benches ranging from less than 50 to more than 200 feet above the present channel and its tributaries. These older benches oftcn are miles in extent and in places are cut by younger and deeper channels. The present streams were mined by hand methods during the early days, later, by wingdams, flumes, and tunnels, and, more recently, by bucket-line or dragline dredges. The benches were worked by hydraulicking, ground sluicing and some by drift mining.
At Hornbrook the river is joined by Cottonwood Creek, which was noted for extremely rich but shallow deposits. A number of lode mines are found here and in the Paradise or Fool's Paradise district, which lies to the southeast. The Shasta River enters the Klamath about five miles south of Hornbrook and both the river and two of its tributaries, Yreka and Greenhorn Creeks, were extremely rich. Between 1850 and 1900 Greenhorn Creek was reported to have yielded $11 million. The Yreka or Hawkinsville district also was nearly as productive. Farther west, the Klamath River was extensively placer-mined between Humbug Creek and the Scott River, especially at Masonic, Skeahan, and Kanaka Bars and at Gottville. Humbug Creek also was very rich (see separate section on the Humbug district). Lumgrey, Empire, and Dutch Creeks, all of which have been mined, enter the river here. The Hazel lode mine, which has yielded more than $800,000, is a few miles north of Gottville. The gold-quartz veins in this mine occur in slate.
Farther downstream are Oak Bar, Beaver and Horse Creeks and Hamburg, where the Scott River flows into the Klamath (see separate sections on the Scott Bar and Callahan districts). At Seiad Valley some 10 miles to the west, substantial mining was done by both dredging and hydraulicking. In the Happy Camp district the river flows around several sharp bends and then turns south. Here the China Creek, Davis, Reeves, Woods Bar, Richardson Bedrock and Muck-a-Muck hydraulic mines were important, as was Indian Creek, which flows into the river from the northwest.
From Happy Camp the river flows in a general south-southwest direction for approximately 50 miles. It runs through the Clear Creek area, where the Siskiyou and Bunker Hill mines are located, Cottage Grove, the Dillon Creek areas (see section on the Dillon Creek district), Rattlesnake Bar, Ti Bar, and Somes bar, where the Salmon River flows into the Klamath (see section on Salmon River). The Klamath River then flows through the highly productive Orleans district in Humboldt County and on to Weitchpee, where it is joined by the Trinity River from the south. At Weitchpec the Klamath River turns west and then northwest for about 45 miles and empties into the Pacific Ocean near the town of Requa in Del Norte County.