The Catskills

Catskill Mountains

The Catskill Mountains, an area in New York State northwest of New York City and southwest of Albany, are a mature dissected plateau, an uplifted region that was subsequently eroded into sharp relief. They are an eastward continuation, and the highest representation, of the Allegheny Plateau...

 began existence as a river delta

River delta

A delta is a landform that is formed at the mouth of a river where that river flows into an ocean, sea, estuary, lake, reservoir, flat arid area, or another river. Deltas are formed from the deposition of the sediment carried by the river as the flow leaves the mouth of the river...

 350 million years ago. Streams flowing off the then-mighty Taconic Mountains

Taconic Mountains

The Taconic Mountains or Taconic Range are a physiographic section of the larger New England province and part of the Appalachian Mountains, running along the eastern border of New York State and adjacent New England from northwest Connecticut to western Massachusetts, north to central western...

 deposited sediment

Sediment

Sediment is naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of fluids such as wind, water, or ice, and/or by the force of gravity acting on the particle itself....

 where the river met a sea (now the Allegheny Plateau

Allegheny Plateau

The Allegheny Plateau is a large dissected plateau area in western and central New York, northern and western Pennsylvania, northern and western West Virginia, and eastern Ohio...

. Eventually the Taconics eroded to their present size and the waters dried up, leaving a mostly flat plain.

During this time period, a meteor

METEOR

METEOR is a metric for the evaluation of machine translation output. The metric is based on the harmonic mean of unigram precision and recall, with recall weighted higher than precision...

 is believed to have struck the area. Panther Mountain

Panther Mountain (New York)

Panther Mountain is one of the Catskill High Peaks, located in the Town of Shandaken in Ulster County, New York. At approximately 3,720 feet in elevation, it is the 18th highest in the range...

 is the remains of its crater

Impact crater

In the broadest sense, the term impact crater can be applied to any depression, natural or manmade, resulting from the high velocity impact of a projectile with a larger body...

.

Two hundred million years ago, as continental drift

Continental drift

Continental drift is the movement of the Earth's continents relative to each other. The hypothesis that continents 'drift' was first put forward by Abraham Ortelius in 1596 and was fully developed by Alfred Wegener in 1912...

 pushed up the Appalachians, the delta region rose almost uniformly into a plateau

Plateau

In geology and earth science, a plateau , also called a high plain or tableland, is an area of highland, usually consisting of relatively flat terrain. A highly eroded plateau is called a dissected plateau...

 rather than breaking up into smaller mountains.