The main ingredient in this landslide is serpentinite, which is formed from serpentinization, a hydration and metamorphic transformation of ultramafic rock from the Earth's mantle. The asbestos mineral that forms from this serpentinite is chrysotile. The possible reason why there was conglomerate bedrock underneath the serpentinite could be because of the glacial till or delta deposits flowing out of the Cascade mountain range as it was forming millions of years ago. After this or while this was all happening, the North American plate and the Pacific Plate were colliding causing uplift that eventually formed Sumas Mountain. As the weathering of this place was happening, the landslide started to slip away from the face of the mountain to its current position.