feutz, the Platte River and the Grant River are probaly the best rivers in Grant County for smallmouths. Smaller streams that run into the Grant that are also good are Rattlesnake and Pigeon creeks. The Wisconsin River on the north side of the county is also great for smallies.
There are alot of bridges over the Grant and Platte that provide access to fisherman. Make sure you get permission from the landowners before walking the streams though. Some landowners are pretty stringent about tresspassing. Feel free to contact me if you want more specific info.