Initially discovered in 1885 and mined periodically to 1943 the Ohra mine produced in the order of 27,000 ounces of gold at grades reported between 3.5 to 20 g/t. The northeast striking vein is reported as 1,200m long with an average width of 0.9 meter^1,2. 

The Takamine and Takamine-Urushi mines were discovered in latter part of the nineteenth century and mined periodically up to 1943. Takamine mine produced 9,654 tonnes of ore with average grades of 5.1g/t gold and 28.3 g/t silver. The vein strikes northeast, has a length of 450 meters, and average width of 1 meter.

Takamine-Urushi mine was estimated to have produced 13,000 ounces of gold between 1896 and 1916. Three northeast striking gold-bearing quartz veins, with lengths up to 350m were mined, the so-called number 2 vein was reported to carry gold grades between 50 to 100 g/t^1,2.  

The Metal Mining Agency of Japan (MMAJ) (Metal Mining Agency of Japan) conducted regional and more detailed studies over the Ohra-Takamine area between 1982 and 1989, eight drill holes were completed as part of this work. Drill hole 60MAH-2 located to the east of the Takamine-Urushi mine intersected two 10-centimetre wide quartz veins with respective gold grades of 12.3 and 13.3 g/t, 100 meters below the deepest mine workings, and approximately 245 meters vertically below surface³.

Four other historic Au mines (Yamada, Kohwa, Kizushi and Maruyama) are reported from outside the application area, located 1 to 3 km to the east and south-east.

Yamada mine was mined by Kagoshima Mining Co. from 1916 to 1930 after which the mining rights were transferred to local people. 7000t of ore was produced with average grades of 4 to 5 g/t Au (~1000 ounces). Kohwa mine was operated from 1946 to 1963 by Takara Mining Co.  Kizushi mine was operated by local people from 1910 to 1926.  Maruyama mine (also known as Oh-shika mine) was opened in 1925 and operated until 1928 with approximately 100 kg (14,100 ounces) of gold produced (METI, 1989³).

More recent MMAJ exploration undertaken between 1979 and 1993 as part of a regional metallogenic study included regional geophysical surveys and prospect-scale surface sampling and drilling.  

• 1979:  Regional gravity survey completed which concluded that known gold deposits were associated with gravity high anomalies.
• 1982:  Geochemical survey undertaken with 415 soil samples and 145 rock chip samples collected. One hundred and five (105) of the samples were analysed via X-ray diffraction to determine alteration mineral type.  
• 1985-1989:  Eight drill holes were completed within the property area (59MAHT-2,3; 60MAHT-2; 61MAHT-2,3,4,5; and 63MAHT-5). Drill hole 61MAH-2 located to the east of the Takamine-Urushi mine intersected two 10-centimetre wide quartz veins which assayed 12.3 g/t Au and 13.3 g/t Au respectively. These intercepts were 100 meters below the deepest mine workings, and approximately 245 meters vertically below surface.
• 1991: Two drillholes (63MAHT -1/2, drilled to 300.1m and 400m respectively) tested a resistivity anomaly along strike and down dip of the Yamada mine. Intercepts of 0.6m @ 0.18 g/t Au from 203m (3MAHT – 1) and 0.6m @ 0.14 g/t Au from 227.35m (3MAHT – 2) were returned.
• 1992: Geochemical rock chip sampling was undertaken to the east of the property with samples also analysed for alteration minerals. 
• 1993: Sixty-four quartz vein and sinter samples were taken from around the Aira mines (Maruyama, Kizushi, Kowa) with six samples returning assays >10 g/t Au (mostly proximal to Maruyama) to a maximum of 154 g/t Au. Based on these high grades a drillhole (65MAHT-1, depth 502.4m) targeted along trend to the north-east of Maruyama mine and was mostly unmineralized with a single interval reporting an intercept of 0.15m @ 0.17 g/t Au from 324.5m.