In 1857 gold was first discovered in the region on the Fraser River which led to a short lived gold rush. Due to the difficult access to the newly discovered gold placers and hostile Indian populations, an alternate access route to the Fraser River, the Douglas Road, was built in 1858 on the Lower Lillooet River.
In the 1862-1864 period, as a result of the discovery of rich gold placer deposits in the Cariboo region of British Columbia, a new wagon road was built in the Fraser Canyon by Royal Engineers. Most of the miners and suppliers used the new route and as a result the Douglas Road through the Lower Lillooet River fell into disuse.
The transient miners panned the Lower Lillooet River and discovered coarse gold but not in large enough quantities that would have made them change their plans and mine the new locations.
Hardrock mining in the area took place on Fire Mountain. Discoveries were made starting with 1896 and in subsequent years adits were driven and gold-silver base metals ore was processed at on-site mills. As described in previous assessment reports the occurrence of platinum in deltaic sands of the Lower Lillooet River at the place where it enters Harrison Lake was noted in 1966. According to the aforementioned reports in the 1970s and 1980s exploration work and processing tests were made on auriferous and platiniferous sands of the Lower Lillooet River.
Alluvial gold and platinum were also discovered on Tuwasus Creek, a western Lower Lillooet River tributary. The sands containing the precious metals occur along a 34 mile ancient river bed, are laterally one-quarter to one-half mile wide, and are occasionally characterized by paired benches flanking the narrow, fast-flowing, shallow river. In most instances the Lillooet River is entrenched within the sands occupying a bed some 100 feet deep. These sands have been classified and re-distributed in post-Pleistocene time over a period of some 10,000 years.
The first record of mineral exploration in the area was in 1896, with the discovery of high- grade gold-copper veins in the Fire Mountain area. A large number of claims were staked, including the Money Spinner, Barkoola and Blue Lead. The Fire Lake Gold Mining Company spent about $50,000 exploring the claims in 1896. Work included exposing the vein for some 300 meters, and driving a 50 meter adit and a 23 meter deep shaft on the vein. A 90 kg bulk sample was taken from the vein in 1897 and shipped to San Francisco, returning an average grade of 127 g/t gold.
A further 1360 tonnes were stockpiled and a Huntington quartz mill was erected on site, however without a crusher, the mill could not handle the ore. An additional 100 meters of tunneling was done in 1897, mostly on the Money Spinner and a stamp mill was erected the following year. Little work was done on the claims until the 1930’s. A 1934 chip sample taken across a 0.9-meter width assayed 5.5 g/t gold. Clean-up of the stamp mill in 1938 resulted in 6750 grams of gold and 1524 grams of silver. Apart from minor sampling, there is little record of any work on the Fire Mountain claims since this time.
The present relief of the Lillooet River drainage system was shaped during various stages of glaciation. At least three major periods of glaciation are recognized. Glaciers formed large ice sheets, which covered the area. Upon melting, these glaciers cut deep, narrow canyons and valleys in the mountains and transported large volumes of gravel to be deposited on the bedrock platform of the Lillooet River valley.
Most of the gravels in the area appear to have originated in the immediate vicinity. The gravels consist mainly of granodiorite and quartz diorite. There are clay and silt layers intercalated between cobble and boulder beds. The main delta of the Lillooet River is composed of material ranging from mud to cobbles of about 20-30 centimeters in diameter. There are few large boulders. The lakeside beaches show stratified layers of very fine black sand containing chromite and tellurides. Gold recovered in this area was very fine with particles of about 0.355 millimeters. Values of platinum, silver, palladium, rhodium and osmium are reported in the sand of the delta.
The source of the gold in the Lillooet River placer deposits is not clearly defined. Surveys of the areas show a thick accumulation of alluvial material eroded and shaped not only by the Lillooet River, but also by meltwater issuing from the Fire and Sloquet Creek glaciers, which tended to impede the gravel transporting ability of the Lillooet River. As the meltwater impeded the flow of Lillooet River, an abnormal amount of gravel was deposited on the bedrock platform.
The real thickness of the alluvial deposits on the bedrock at the terraces is unknown, but according to geomorphologic evidence (the escarpment of the present riverbed), it is indicated to be about 50 meters on average.