Geology
The drainage basin of the river has many geological formations such as a wide belt of granite crossing the Kwinium river to the south.
Gold mining in the river basin began in 1900 after panning of the surface gravels uncovered coarse gold. Conglomerates were also noted in the bed of the river. Basalt formations were also recorded in the head waters between the Tubutulik River and Grouse Creek.
The radioactivity recorded in the area was tested and found to be concentrated in the Tubutulik River and its tributaries at many locations. Three areas on the Tubutulik River contain abnormal radioactivity. Samples were taken from the granite rocks of the river valley including the tributaries and tested. The test results revealed radioactive uranium concentrations of more than 0.2 % of equivalent uranium.
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