Hi JG, I'm going to try and critique this... kind of challenging, because, hey you taught me a lot of what I know... but bear with me, and let me know what you think!
I see what you were trying to do, using the trees to frame the bridge, however I'm not sure if it really worked in this case... although you have good use of DOF with both the bridge and the trees in focus, the sharp lines of the trees tend to grab my eyes, long before the rounded bridge does. Since you were going for the bridge, I'm guessing as one of your main subjects, I would say that the lighting did not go with your intentions. The greyness of the day tends to give the bridge a soft look to it. In your photography I know you like to go for something in the foreground to give the photo more depth, but I think that the trees somewhat overpowered the photo. I think it would have been more effective possibly with the tree on the left, bare, and not with the dull green. Seeing as how the colors are very dull in this photo, I might suggest that you try this in black and white. This is easily accomplished with one step in photoshop, and then you could play with contrast and levels. As it is, the entire picture seems to be covered by a grey film, which mutes what could be a very beautiful scene (though common for me ;-)) I like your use of composition... following the rule off thirds in your breakoff from the river to the sky. I also like the fact that you didn't center the bridge... and that it comes out of the bottom left hand corner, leaving some lines for you to follow when you finally get past the trees to the bridge. Hopefully this critique helps... and let me know what you think!
This photo has a lot of detail but I think this created too much "clutter" in the photo. I can see that the emphasis is on the bridge but some of it is covered by the foreground tree branches. Infact, the trees seem to overpower the photo a lot in my opinion. I think you probably have a lot of wonderful spots around the missisippi to photograph that choosing this particular angle on a bridge does not engage me as well as it should.
I think this photo is lacking a good point of interest, the bridge is there, but it spans the whole frame making the eye wander around looking for something more compelling to look at.