How to Find the Best Grass Fed Beef

Buying Grass Fed Beef seems like a simple thing, you go to a store that carries it or you join a CSA, perhaps you buy at the local Farmers Market or order it online from a Farmer. The act of purchasing Grass Fed Beef is an easy one; you swipe the credit card and voila, you go home with yummy meat.  But how do you know which Grass Fed Beef to buy? How do you know if its Pasture Raised Grass Fed