Gibbon Falls

Gibbon Falls, on your left in about half a mile. Pull in, and watch for oncoming traffic as you cross. There's parking and a long viewing walkway, and eighty-four feet of the Gibbon River coming down over what's left of the caldera rim. Once you're out of the car, turn and look back across the road. All day I've been telling you this volcano is too big to see. That rock wall across the road from the falls is the inner rim of the Yellowstone Caldera. That's it. That's the edge of the thing, standing beside the pavement. Think about the day you've just had. Old Faithful, West Thumb and the north half of the lake all lie inside that rim. Norris, back up the road, sits just outside it, close to the rim and its ring fractures, so coming down this road you've crossed back in. Most of this loop has run inside the volcano. Two of the three big eruptions rank as super-eruptions. The first, two point one million years ago, coated ground with ash as far off as Missouri, and threw out an estimated six thousand times the volume of Mount Saint Helens in nineteen eighty. Will it go again? The park says another caldera-forming eruption is theoretically possible but very unlikely in the next thousand or even ten thousand years, and more than thirty years of monitoring have shown no sign of an imminent smaller lava eruption. Turn left out of the lot. One last stop if you want it. Terrace Spring is on your right, less than a mile before Madison Junction, with a short boardwalk and a small lot.