Porcupine Creek was first prospected in the early 1890’s and by 1896 several claims were located principally for hydraulic mining. Panning yields, however, were disappointingly low for the times, averaging only $1 per pan. The creek was the site of hydraulic mining in the 1930’s, when three giants with 4-in. nozzles were used. Mining since then has been intermittent, in the late 1950’s, in the early 1960’s, in 1975, and during the 1980’s.
Porcupine Creek flows in an easterly direction for 20 km, and then it joins Mammoth Creek to form Crooked Creek. Bonanza Creek, the principal tributary enters Porcupine Creek from the south about 8 km above its mouth. Yankee Creek, also a north-flowing tributary, enters Porcupine Creek about 10 km above the mouth of Bonanza Creek. Placer gold was mined in the upper third of Porcupine Creek; along its tributaries, Yankee and Bonanza Creeks; and at small downstream locations. Much of the lower two-thirds of Porcupine Creek was unmined.
Gravel in the mined sites of Porcupine Creek is composed of subangular and slabby boulders and cobbles of schist and quartz; most boulders are 30 cm in diameter or less but some are as much as 1 m in diameter. Gravel is 3 to 8 m thick and is overlain by as much as 1 m of muck. The paystreak is 30 to 70 m wide. Less than 2 m of the lower gravel was put through the sluice-boxes during hydraulic mining in the 1930’s, because the high values occurred primarily on, and in, the underlying bedrock. The high-powered jets of water from the 4-in. giants were effective in cleaning and ripping up the fractured bedrock. Gold recovered was coarse and ragged and contained nuggets weighing as much as 3 ounces.
The largest nugget recovered was 8.5 oz. Although abundant unmined gravel remains in the middle and lower stretches of Porcupine Creek, the grades are too low to be profitably mined at current economic conditions. Small-scale open-cut mining has been attempted at least three times during the 1970’s and 1980’s on the lower part of Porcupine Creek, and each attempt was unsuccessful.
John Schnabel, grandfather to Parker Schnabel from Gold Rush fame, owned the Big Nugget Mine on Porcupine Creek.
