South of Toronto Zoo and between the Rouge and Little Rouge Rivers, the Hogback tableland is an interfluvial, or between streams, ridge of preserved recreation land among a 400-acre forest, the largest surviving in the Toronto metro area.eventeen miles north of the lakeshore, the hills and valleys of the Oak Ridges Moraine rise 820 feet above lake level and feed the aquifer that provides water for 200,000 people within Toronto.