Try like 60 plus miles north of the scottsbluff monument. Sioux County has very few people who live there, mostly farmers and ranchers.
If this is Chance someone dumped him there. I live just west of the monument and drive the route he supposedly walked all the time. There is no reason he would have walked up there, especially in that storm. We got like 3 inches of rain that night, it was brutal. Besides, the Monument is closed and I don't see even a severely intoxicated person making that hike in a down pour, let alone in the daylight.