how do you tell the difference between a large mouth bass and a small mouth bass?

Largemouth bass is an olive green, marked by a series of dark, sometimes black, blotches forming a jagged horizontal stripe along each flank. The upper jaw extends beyond the rear margin of the orbit... eye socket.

Smallmouth bass is generally brown with red eyes, and dark brown vertical bands, rather than a horizontal band along the side like a largemouth. The upper jaw of the smallmouth bass extends to the middle of the orbital bone.

I think that the real experts answer this by saying that the jaw hinge on the side of the largemouth's mouth extends back past its eye. The jaw hinge on the side of a smallmouth's mouth does not extend back past it's eye. In my area the colors of the two fish are so different that you can always tell the difference. The largemouth has deep green coloration on it's sides and the smallmouth is more of a redish bronze color. The colors can vary from area to area and from one body of water to another but as a general rule the largemouth will be some shade of green to almost black and the smallie will be bronze. Depending on where you live you may run into spotted bass which is a combination of two. It has a green pattern on it's sides but the jaw hinge does not extend past the eye. With this explanation you should be more confused than you were before you ask the question. I know I am.

very simple...

A largemouth bass on its side has a dark green stripe going down it. The dark green stripe seperates the its green back from its white stomach. Also, a largemouth, shocking i know, has a big mouth that you can almost fit your fist in.

A smallmouth has an olive-brown back with a white stomach. It is usually leaner than a largemouth and has a much, shocking again, smaller mouth.

With mouth shut the back corner of fishs jaw does not extend past the eye on a small mouth and t does on a largemouth.

Bout' the easiest way be their mouths ie., Largemouth bass's mouth (hinge of it) will extend past his/her eye like in pic http://en.wikipedia.org/wiki/File:Largemouth.JPG

Smallmouths mouth doesn't http://en.wikipedia.org/wiki/File:Smallmouth_bass....

Colors and size varies, a' Smalley is somewhat bronze and a' LM more ta' the greenish side and larger...