I'm also skeptical of water. The ground wasn't frozen and there are abandoned farms all around North Iowa, where you probably wouldn't notice someone driving up. A long driveway and a grove can give a lot of cover.

If someone disposed of the body that quickly and with that much confidence, they knew at least one of the rural areas around MC as well as the town itself. Maybe someone who went to NIACC? Possibly a recent graduate? If that person was going to leave the area soon, there are psychosocial reasons that might make sense of a motive. Whoever it was needed to be someone whose friends wouldn't think it was odd for him to be out at 3-4 in the morning. Possibly a hunter, or maybe a war veteran (Gulf War I is right for the timetable); if he pulled it off with the kind of precision we're looking at, he had to be comfortable with handling a dead body. Maybe a law enforcement major. The same person who can justify doing this and not "give it away" over time is probably someone who is "above suspicion" in some way. Does this make any sense?

Anyway, the direction of travel is conjecture since you could make a loop on the country roads around MC in little time. More important would be that you know where you're going, and that's going to be somewhere you've spent a good deal of time before. Maybe that's a lake and maybe not.

Partly because of all this, I don't think Pruin was connected by perpetrator. Why leave one body visible and hide the other one? Nothing seems to rule out suicide there either. He was making random accusations about drug dealing and apparently thought people were out to get him. Maybe all this was right and maybe it was a missed sign of mental illness (bipolar, esp.). Maybe he just snapped. I don't know. Everyone close to a suicide has a reason not to want to believe that's what it was, and these are old-fashioned people. Not to step on anyone's toes, but I think that's kind of a dead end. Although I wonder what the perp thought of the Pruin case - maybe simply that once again the authorities were clueless. Heck, maybe there's something there -- did he apply to MCPD and not get the job? Just a thought.