 He's erosion good or bad? Let's think in big scales. Look at the Wind River range of mountains here in Western Wyoming. Here, mountains are being built as the edges of buckling landmasses collide together. The highest places in Wyoming are here, including Gannett Peak. Wyoming's highest major in a whopping 13,804 feet. Now, even as these mountains are uplifting, there have been tens of thousands of feet which have been worn away. Erosion doesn't wait until mountain building is done. Wind, weather, and the force of gravity have chipped away at the uplifted and exposed mountain ranges. Bits of mountain, large and small, follow the laws of physics in their journey to the lowest point they can. Most of these bits of rock and soil are gathered up in water. Small trickles at first, building into creeks, streams, and rivers until the laws of physics and the decrease in the energy they carry force them to come to rest. Again, think it on the big scale. That's where tens of thousands of feet of mountain that aren't there anymore went on downstream. That's where Louisiana came from. Erosion is a natural phenomenon. It's going to happen, but it's a reasonable responsibility for us not to accelerate it. From the University of Wyoming Cooperative Extension Service, I'm Eric Peterson.