Sequence of Events question

After Ketcham was kidnapped, Cordona split off to go get the cavalry. But this was before Sheriff Hendricks sent his men out to block the roads out of the area. So how is it that they were already in place to intercept Cordona by the time he got to that point? Are we supposed to assume that the Sheriff's station the men were dispatched from was a lot closer to that point on the road than Cordona was when he split off from his friends? Or is this just an inconsistency that was missed in the making of the movie? Just curious.