I'm sorry but I checked with 2 of our noted local genealogists and with some very old local history books and there was never a Salt Creek Twp. in Union County, Ohio The ladies said there are areas called Salt Creek in southern Ohio but not around here.
Maybe you have the wrong state.
Also, in 1850, part of the Van Wert County census is on the Union County reel, could your Salt Creek Twp. be in Van Wert Co??