SPEARFISH, S.D. — A bid for a West River road win went sideways in a hurry for the Mitchell High School football team on Friday night at Lyle Hare Stadium. In a span of less than five minutes late in the second quarter, the Kernels went from driving deep in opponent territory in a tie game to staring down a 20-point deficit, as Spearfish ran away with a 47-27 victory. It was a series of swift, decisive blows by the Spartans, who snared a Kernel …