Grand Canyon of the Yellowstone is not at all the most famous part of Yellowstone, but it may very well be the prettiest. My coworker, who once spent two summers working in Yellowstone, told me it was his favorite. It was a positively spectacular sight.
Grand Canyon of the Yellowstone is a water erosion feature, carved through the soft volcanic rock by the Yellowstone River. It looks less unusual and is certainly less dynamic than the erupting features on the west side of the loop road, it's still utterly amazing, featuring a beautiful waterfall at one end, with upper and lower cascades.
Our first stop was an overlook called Artist Point.
We descended the steep Uncle Tom's Trail, 150 meters down. The park brochure promised, "an unparalleled canyon and waterfall experience."
Climbing back up the steep trail wasn't as exhausting as it had sounded. We were back at the car in no time, and very glad we had taken the time for the trail.
We had thought we were done exploring the Canyon area, but then I read in National Geographic's Guide to the National Parks of the United States (an excellent reference that everyone who loves this stuff should own) about the other trail down to the Lower Falls on the south side of the canyon: "Standing beside the green river where it suddenly drops into space is one of the most exciting experiences in the park." We felt we had to go back for it the next day.
What an experience! I think the Canyon area was better than the geysers. Less unusual certainly, but it definitely stands out as one of the steepest and most marvelous canyons I've ever seen. It was all incredibly exciting, one of the most worthwhile adventures in Yellowstone.
Distance hiked: at least 6+ km
On to Norris Geyser Basin.