The Rossland Monzonite, centered on the town of Rossland, extends north to Monte Cristo and Columbia-Kootenay mountains and east to the vicinity of Lookout Mountain. It is the host rock (along with adjacent country rock) for the storied gold mines of Rossland. In the last 190 million years the region has endured tumultuous geological disruption. In this time the Rossland Volcano has been deeply buried, deformed, metamorphosed and finally partially uplifted again. As a result the Rossland Monzonite intrusion now lies exposed as outlined above on Edmund Kirby's 1906 map. It takes the approximate shape of the valley from Warfield up to just west of Rossland. The intrusion itself has been deeply eroded by Trail Creek.For further reading. "The Story In The Rocks" - The Geology of Rossland, B.C. is available in the Museum Gift Shop and other book stores.