Europeans began settling the river valleys around the Metacomet Ridge in the mid-17th century. Forests were cut down or burned to make room for agriculture, resulting in the near complete denuding of the once contiguous forests of southern New England by the 19th century. Steep terrain like the Metacomet Ridge, while not suitable for planting crops, was widely harvested of timber as a result of the expanding charcoal industry that boomed before the mining of coal from the mid-Appalachian regions replaced it as a source of fuel. In other cases, ridgetop forests burned when lower elevation land was set afire, and some uplands were used for pasturing. Traprock was harvested from talus slopes of the Metacomet Ridge to build house foundations; copper ore was discovered at the base of Peak Mountain in northern Connecticut and was mined by prisoners incarcerated at Old Newgate Prison located there.