The Yankee Boy occurrence is located on the western side of Tranquil Creek, approximately 1.5 kilometres northeast of the creek mouth, and 19 kilometres northeast of Tofino, B.C.

The Tofino Inlet Pluton, of the Early to Middle Jurassic Island Plutonic Suite or the Mesozoic and/or Paleozoic Westcoast Complex, intrudes Paleozoic Sicker Group rocks. The plutonic rocks consist of quartz diorite and granodiorite. The Sicker rocks include volcanic breccias, tuffs, greenstone, greenschist and dikes and sills of andesite porphyry. The plutonic and volcanic rocks are transected by northeast trending faults.

The showing occurs in an area underlain principally by quartz diorite. Precious metal bearing quartz veins were worked in 1940 and 1941. In 1940, 0.35 tonne of ore was shipped and assayed 426.17 grams per tonne gold, 196.80 grams per tonne silver and 0.50 per cent copper (Minister of Mines Annual Report 1940, page 42). In 1941, 0.43 tonne of ore was shipped and assayed 121.20 grams per tonne gold, 52.80 grams per tonne silver and 0.20 per cent copper (Minister of Mines Annual Report 1941, page 44).

Reports indicate that the workings were subsequently buried when logging roads were constructed in the Tranquil creek area in the early 1960's and mid 1970's.

In 1983 and 1984, Euro Petroleum Corp. completed a program of prospecting, geological mapping and rock and soil sampling on the area as the Tranquil property. Rock samples taken in the area of the old workings assayed as high as 0.75 grams per tonne gold (Assessment Report 12034). These samples were taken from 2 to 5 centimetre wide quartz veins in pyritized chloritically altered granitic country rock.

In 1988, D.H. Wood completed a program of prospecting. This included the blasting of several pits which revealed a 20 to 45 centimetre wide northwest striking quartz vein containing approximately 5 per cent pyrite and minor chalcopyrite (Assessment Report 17764).

A small soil and rock sampling program over the Yankee Boy area did not result in encouraging results.

In 2017, Selkirk Metals Corp. collected soil, stream sediment, and rock samples along the southern extent of the Fandora Mine road, upslope from the Yankee Boy prospect. Seven soil samples (SL17-37 to SL17-43) form an anomalous area, consisting of gold values ranging from 19 ppb up to 4.27 ppm. Arsenic values are also significantly high within the interval and demonstrate a positive correlation with gold. The anomaly is located directly below a 10 m tall cliff exposure consisting primarily of dark grey andesite. The andesite contains a vein-like structure that has undergone significant greenschist metamorphism. The vein-like structure contains high concentrations of chlorite with variable quartz and pyrite. The inferred trends of structures and soils containing gold suggest that mineralization associated with the Yankee Boy trends approximately 62° NE. This trend is similar to the overall trend of the Fandora vein system (Assessment Report 37432).