Ontario Trap Rock, a division of R.W. Tomlinson Limited, is a specialty aggregate quarry located near Sault Ste. Marie, Ontario. The 1,000 acre site contains more than 80 million tons of aggregate known as "Diabase". More commonly referred to as "Trap Rock", this aggregate is a very hard, durable material with physical properties far exceeding the most stringent railroad specifications. Our material is currently used throughout the Great Lakes region by a number of Class I, Regional and Shortline Railroads.