The Manson River placer occurrence is located on an old placer site along the Manson River (near the old settlement site of Manson Creek). This occurrence covers that section of the Manson River which stretches from the informally named Kildare Creek (093N 057) and continues downstream to approximately 1 kilometre above the Manson Lakes. The underlying bedrock along this section of the river includes rock types which belong to the Cassiar, Slide Mountain and Quesnel terranes. The variance of bedrock is due to the Manson fault zone which is associated with all the placer occurrences in the area between Germansen Landing and Manson Creek. The rock types found along this structure are ultramafics, listwanitic rocks, slates, argillites, sandstones and quartz wackes.
Placer gold was first discovered on the Manson River in 1871 and gave rise to the Manson Creek placer gold camp. Placer mining along this drainage system has occurred continuously since that time. The bedrock is covered by glacial material which is in turn covered by postglacial gravels. The auriferous gravels are those that lie directly on the bedrock and the postglacial gravels. The majority of the interest has been the surrounding bedrock benches above the present level of the river. Past mining methods included hydraulics, underground, dredging, shovel and dragline and sluicing. Operations during the late 1980s consisted of moderate to small operations which only operated during the summer months. Gold found by these operations has ranged from fine to coarse in size and semi-round to flat in shape. Jim Thomas ran a placer operation in 2002.
Placer gold production from the Manson River as recorded by Holland, 1950 (Bulletin 28) is mainly for the periods between 1874 and 1910, and between 1931 and 1945. The total amount recovered is reported to be 358,032 grams.