About a mile southeast of Ashfield Center, near the Williamsburg Road intersection, the South River crosses Route 116 for the last time (if you are heading west). It is quite small at this point, only a first or second order stream. (Stream orders: when a stream first becomes perennial, it is a first order stream. When two first order streams join, it becomes a second order stream. When a first and second order stream join, it is still a second order stream. When two second order streams join, it becomes a third order stream. And so on.)