The photograph above is a view of the Presque Isle River Gorge of the Porcupine Mountains State Park in Michigan's Upper Peninsula. The photograph was taken on a forty foot high cable bridge that crosses over the river. The wind was moving briskly, which made it impossible to keep the foliage from moving throughout the longish exposure of six seconds.
One of the largest holes in this section is a staggering fifteen feet, maybe more, in diameter. Truly stunning. During springtime most of these strange holes are not visible due to the increased water flow. Fall makes a perfect time to visit the Porcupine Mountains State Park, the floe of water is much lower making all of the parks waterfalls more photogenic.
Technical details: Canon 7D, Canon 24-105L lens (@35mm), 3-stop Neutral Density Filter, CPL Filter, ISO 100, F/11, 6 seconds.