Year: 420 million years ago
The Allegheny Plateau is a broad landform that makes up almost all of the Southern Tier of New York State. Geologically, it is part of the Appalachian Mountains. The Plateau is a worn-down portion of that mountain range, with remnant rolling hills and many lakes and rivers. It lies mostly to the west of the high peaks of the Appalachians, and stretches in a southwesterly direction through Pennsylvania, Ohio, West Virginia, and Kentucky, paralleling the high ridges.
The Plateau's northern end is in central New York State. In New York State it stretches as far north as Syracuse, as far east as Albany and Monticello, and as far west as Jamestown.
During the last Ice Age, the retreating glaciers carved out New York's famous Finger Lakes and left a series of low-lying hills (terminal moraines) across the region.
Most of the Plateau was historically heavily forested with good soils. The Iroquois used the Plateau for both agriculture and hunting. When Europeans entered the region they cleared much of this aboriginal forest and turned it into farmland. It is New York's breadbasket, and the heartland of New York State's important dairy industry.