The Engineer occurrence is located at Railroad Creek gorge on Railroad Creek, 7.5 kilometres north of its confluence with the Lillooet River.
Regionally, the area lies on the east flank of the Coast Plutonic Complex. Several large roof pendants of fine clastic sediments and volcanic rocks of the upper Triassic Cadwallader Group and lower to middle Jurassic Ladner Group are encompassed and intruded by large granitic intrusions. These are intruded by feldspar porphyry dikes.
Locally, pyrite and rusty gossan alteration is abundant along a shear or fault zone exposed in the Railroad Creek gorge. The host rocks are altered andesites and north west-trending, quartz feldspar porphyry dikes.
In 1988, two samples (H-Pass-1 and 2) assayed 0.15 and 0.03 gram per tonne gold, 2.6 and 5.6 grams per tonne silver with 0.237 and 0.769 per cent copper, respectively (Property File - Chemex Labs Ltd. [1988-10-13]: Certificate of Analysis - A8824969 - Chevron Canada Resources Ltd. - Hurley).
In 1994, 16 channel samples were taken continuously over 10 metres of silicified andesite and quartz feldspar porphyry dikes with abundant pyrite. Several old bulldozer trenches and cuts were also resampled on the east side of the property. The most encouraging copper values are associated with altered andesite. The best results obtained were from sample Eng94-RC23, a chip sample across 3.5 metres of silicified quartz feldspar porphyry containing pyrite and chalcopyrite. The sample yielded 0.10 per cent copper (Assessment Report 23623).
In 1979, a program of chemical sampling, geological mapping and prospecting was completed on the area as the RRPASS 1-10 claims. The eastern half of the Engineer claims, previously staked as the Hag claims, was explored in 1983 by Canadian Nickel Company Ltd. In the same year Noranda Exploration Company, Ltd. explored two gossan zones to the immediate west on the Don claims. In 1988, Chevron Minerals examined the area as the Peak 1-2 claims. In 1989, an exploration program was conducted at the bottom of Railroad gorge. The program consisted of soil, rock chip and stream sediment sampling and detailed geological mapping. In 1993, the claim geology was mapped by J. Riddell. The current owners and operators of the Engineer claims are R. Jordan and P. Jordan.
