You are definitely in the fringe area of signals from Sioux City. I've taken the liberty of running a search based on an estimate of your location (given the relatively flat terrain great precision is not critical);
https://rabbitears.info/searchmap.ph...&study_id=3832
If I was in you area, I would consider using a Winegard HD7698P paired with an Antennas Direct 'Juice' preamplifier. Aim toward Sioux City (aprox. 263° compass). At you location, height matters. I would not hesitate to use a tripod and 10 foot mast at the roof peak. Also, if there are any trees blocking the path, they need to be avoided, either by mounting above them or to the side if possible.
Though the conditions are challenging, I thinks there's hope of receiving KTIN, KTIV, KMEG, KPTH and KCAU.
A premium option would be Rohn-25 tower, Antennas Direct 91XG (UHF ant.), Stellar Labs 30-2476 (HighVHF ant.), Antennas Direct UHF / VHF Antenna Combiner and Juice preamplifier.