Production of placer gold on the Tulameen River was first reported in 1877, and may have commenced as early as 1860. By 1887, most of the shallower gravel deposits mined along the Tulameen River are reported to be exhausted.
The community of Tulameen and the Tulameen River derive their name from a Thompson Indian word meaning red earth. A steep bank of the Tulameen River four miles north of Princeton was the source of the much-prized red ochre for which the Indians travelled from afar. The settlement of Tulameen was earlier known as Campement des Femmes, or Otter Flat.
The Tulameen River flows northward for 30 kilometres from the Cascade Mountains to Grasshopper Mountain, where it changes course and continues eastward for 10 kilometres to the town of Tulameen. The river then flows southeast for 25 kilometres before entering the Similkameen River at Princeton.
The upper part of the river runs through a wide valley extending from its headwaters in Paradise Valley southward to Champion Creek. The river continues through a narrow rock-walled canyon between Grasshopper and Olivine mountains to the mouth of Olivine (Slate) Creek. Here, a broad valley floor with deep gravel deposits opens up and continues past the towns of Tulameen and Coalmont to a point 2 kilometres below Granite Creek. The river then cuts through a canyon, where extensive gravel deposits are relatively scarce. About 5 kilometres west of Princeton, the river enters a broad valley and flows over a gravel bed with gravel benches on either side, extending to the Similkameen River.
Gold and platinum deposits have been found over the lower 40 kilometres of the river. Most recorded production and exploration has occurred along two stretches. The upper stretch begins about 2 kilometres west of Tulameen and continues up the river for 12 kilometres to the mouth of Champion Creek. The lower stretch begins at Coalmont, just above the mouth of Granite Creek, and continues southeast for 19 kilometres to Princeton.
Metals found along the Tulameen River tend to occur in old sinuous channels buried deep below glacial gravels, which contain only spotty values. Gold occurs in rough, angular or slightly flattened and rarely well-flattened nuggets. Some of the nuggets contain abundant white quartz. Platinum forms small rounded grains of uniform size. They are smaller than the gold nuggets and are commonly pitted. Larger platinum nuggets often have a coating or included crystals of cumulate chromite, sometimes with intergrown magnetite and inclusions of olivine. The gravels worked along the river also yielded black sands containing fine platinum, in addition to gold. The ratio of gold to platinum recovered in this part of the river is about 4:1, but decreases upstream.
Black sands produced by a dragline 4 kilometres above Princeton assayed 251 grams gold per tonne and 40.1 grams platinum per tonne. Farther upstream, about 3 kilometres below Coalmont, a sample of panned black sand assayed 27 grams gold per tonne and 21 grams platinum per tonne. A series of shafts and pits at this location below Coalmont encountered gravels averaging 1.1 grams of gold equivalent per cubic metre for combined gold and platinum. Similar workings at Petersen Flat, 5 kilometres west of Princeton averaged 1.2 grams of gold equivalent per cubic metre for combined gold and platinum. Measured geological reserves on the Ruby lease, 6 kilometres below Coalmont, are 268,000 cubic metres grading 1.38 grams of gold equivalent per cubic metre for combined gold and platinum. Bulk sampling in the immediate vicinity produced 77.8 grams of coarse gold from 15.3 cubic metres of gravel.
High platinum prices during the mid to late-1920’s prompted a revival of placer mining along both the upper and lower sections of the river. Three prominent operations, located 3 (Guest lease) and 6 (Ruby lease) kilometres below Coalmont and 4 kilometres above Princeton (National Holdings Ltd.), were active between 1924 and 1929 on the lower part of the river. Production from the Ruby lease for 1926 amounted to 778 grams of gold and 280 grams of platinum. Minor production occurred during the 1940’s and 1950’s, largely within 5 kilometres of Princeton. This activity was centred 3 kilometres west of Princeton, where for example, R. Haigh recovered 1534 grams of gold and 420 grams of platinum from 760 cubic metres of gravel in 1941.
Gold production for the entire river between 1885 and 1945 is estimated at 297,000 grams.