The New York Strip meat is cut from the cows loin part of the sirloin.
The strip of steak that is the New York Strip is from a muscle that does very little work in the cow.
The New York Strip is cut from the short loin which is colored in red in the image below.
The New York Strip gets it's name because it's association with New York City.
Here's an image depicting where different meats come from cows.
