Headward Erosion – Canyonlands National Park, UT. In this view from Grand View Point in Canyonlands National Park, three stream branches (the middle one is labeled with the placemark) are experiencing headward erosion. Headward erosion allows streams to lengthen in the upstream direction. As seen from this viewpoint, in which direction (right or left) are the streams lengthening? Choose one: right (west) left (east)