The area of the Rainbow 1 showing is underlain by volcanics of the Lower Jurassic Telkwa Formation, Hazelton Group. A stock of granodioritic quartz feldspar porphyry of the Late Cretaceous Bulkley Plutonic Suite intrudes volcanic rock. The stock is known as the Sunsets stock.

An area of talus near a granodiorite-andesite contact yielded 0.026 gram per tonne gold, 5.4 grams per tonne silver and 0.22 per cent copper (sample WR-36, Assessment Report 21765). The sample consisted of andesite with up to 10 per cent disseminated pyrite. Other nearby samples of quartz monzonite talus were elevated in silver and lead. A sample of andesitic float about 450 metres to the southwest of sample WR-36 assayed 0.6 gram per tonne gold, 13.1 gram per tonne silver, 0.57 per cent copper and 0.078 per cent zinc (sample YR-25, Assessment Report 21765). This sample contained 2 to 5 per cent pyrite as fracture fillings and a trace of chalcopyrite.

Refer to Loring (093L 036) and Fly (093L 045) for related details.

Refer also to King (093L 041) for general information on the El Toro property, a large property that was worked by of Lions Gate Energy Inc from 2007 to present (2015) and encompassed the Sunset Basin area which contains this showing.