I just read the article on the main page about river fishing for smallmouths. How shallow is too shallow? In a deeper area of the river how long of a span are we talking. I guess the main question is how much water do smallmouths need to inhabit a river? I've got a few areas near me that run deep 5-10 feet and slowish but they're not very long and the river is maybe 25-50 feet wide. The entire river has large rocks throughout it. As soon as I get my license renewed I'll be out trying it for myself. What do you guys think?

I don't really think there IS a "too shallow" when it comes to Smallies.  I've seen it where their dorsal fin is poking out of the surface.  Living in Pittsburgh, you get used to fishing River Smallies, as you have 3 rivers right in front of you.

I have caught 17"-19" fish in very small rivers (almost streams) in northern Virginia. One "river" that I have the most success in is about 30 ft wide at the widest and averages about 2" deep with the occasional 4"-5" stretch. Like Racerx said I don't think there is a "too shallow".

The rivers I fish are considered shallow as    most people either wade or float in a kayak. Nearly all of my fish come out of four feet of water or less. I do feel that the odds of getting bigger fish goes up when you are fishing near to deeper water. 

The last trip I took out in the river late last winter I was catching them up by the banks, in about 6-inches of water. You can find them just about anywhere. I would say though I've never seen them less than about 3-inches, unless you're looking for fry. 

I've seen fat 20" smallies sitting in shin deep water over some gravel past a bend catching baitfish as they come around.

One of the better spots within an hour of my house here in Minnesota for smallmouth bass is in a small river that is literally too shallow and rocky for a standard boat to access.  Its surrounded by private, wooded and agricultural land and every once in a while there is a canoe/kayak access but the fact that its inaccessible to most with a bigger boat is what makes is SO under fished.  The best areas are what the guys in this thread have already indicated - find some rocks and current near some deeper water if you can and there are surely to be some bigger bass hanging around.

I fish a couple shallow, rocky rivers in PA, the Juniata and the Susquehanna, the Susquehanna is really wide but average depth isn't much. Some areas are 20' deep and other spots are a few inches but I've caught large 5lb smallmouth out of 2' of water. In the winter I found a hole holding fish that was a little over 8' deep, and it was maybe 40 yards long and 50 yards wide, I caught 11 smallmouth there on a hair jig and the smallest fish was 15" with the largest being 20.5" and weighing 4lbs 11oz. As long as there is enough oxygen and food, the smallmouth will be there.

I've caught them spots as shallow as a foot or two.  First time made me think twice about avoiding the shallows.