The area of the Olga occurrence is underlain by the southern contact of the Middle Eocene Coryell batholith with the Upper Cretaceous Sophie Mountain Formation. The Coryell Intrusions are generally coarse-grained and range in composition from syenite to monzonite and granite. The Sophie Mountain Formation comprises conglomerate with thin interbeds of argillite and siltstone.

By 1987, two Olga claims were reported under development. Three "ledges" or (veins?) are reported, one averaging about 2 metres in width and another about 2.4 metres in width. The third was not described. Assays of surface ore from the 2.4 metre wide vein range up to 3.35 grams per tonne gold, 448 gram per tonne silver and 54.55 per cent lead (Hodges, 1897).

A parallel vein was reported on the Abe Lincoln group of three claims. The vein strikes northwest and has been traced for over 300 metres. The gangue is quartz carrying gold and galena. By 1897, a 15-metre shaft was down on the footwall and a crosscut had been run at the bottom for 13 metres, from which drifting had begun. The vein, as defined by the crosscut, is 12 metres wide.

In 2006, Major Gold Limited conducted a mineral exploration program on the Portland Project. This included prospecting, grid surveys, soil geochemistry, rock sampling, and magnetometer surveys. Results from the soil grid geochemistry survey and the magnetometer survey showed anomalous gold, silver, copper, arsenic, lead, and zinc patterns correlating to known mineralization on the property.