What is a "Notch"?

In New Hampshire, there are many Notches... Franconia Notch, Grafton Notch, etc.

According to Wikipedia (http://en.wikipedia.org/wiki/Mountain_pass)


In a range of hills, or especially of mountains, a pass (also gap, notch, col, saddle, bwlch, brennig or bealach) is a saddle point in between two areas of higher elevation.^{[citation needed]} If following the lowest possible route through a range, a pass is locally the highest point on that route. Since many of the world's mountain ranges have always presented formidable barriers to travel, passes have been important since before recorded history, and have played a key role in trade, war and migration.

and...

There are many words for pass in the English-speaking world. In the United States, the southern Appalachians more commonly use the word gap, and notch is often heard in New England. Scotland has the Gaelic term bealach (anglicised "Balloch"). In the Lake District of north west England, the term hause is often used, although the term pass is also common — one distinction is that a pass can refer to a route, as well as the highest part thereof, while a hause is simply that highest part, often flattened somewhat into a high level plateau.