A neighbor (and by "neighbor" I mean lives 3 miles down the road) said that the previous homeowner, two owners ago, did that. Well, he didn't use dynamite, but he did dam it up with something and made a swimming hole. The only problem with damming it up is that in heavy rains the creek floods and will wash just about anything away. After hearing this from a neighbor, I think it may have explained what the heavy cable was spanning across the creek at two areas, but they were snapped. I thought maybe it was for keeping cattle in, but I guess it held something else together.