The politics of the Oak Ridges Moraine in southern Ontario, Canada, have centred on the question of how to preserve this extensive natural resource that is increasingly threatened by human modification. Although preservation of the moraine was first suggested in the 1940s, and intermittently over the subsequent fifty years, it was not until 1991 that the issue achieved prominence in political discourse. For the ensuing decade, use of the moraine was hotly contested between the interests of local residents, developers and environmentalists.