The Late Triassic Whistle Creek Formation underlies most of the property and consists predominantly of westerly dipping andesitic tuffs with minor interbedded clastic sediments and limestone lenses. The Copperfield conglomerate is a limestone boulder conglomerate that is found at the base of the Whistle Creek Formation and overlies the Hedley Formation of interbedded clastic sediments, carbonates and minor tuffs. Jurassic Cahill Creek granodiorite crops out on the eastern part of the claim. Hornblende-feldspar porphyry sills, also of Jurassic age, cut the Triassic rocks. The clastic sediments of the Hedley Formation are hornfelsed and have undergone calcic alteration.