On my fourth day, I went on a ski tour riding a Bombardier out to the Grand Canyon of the Yellowstone. We started with a ski from the Canyon visitors center, up a road to the canyon rim. We proceeded to ski on the north rim of the canyon for about a mile. It was the most spectacular cross-country ski I had ever done. Below us was a canyon over 1,000 feet deep with a pink rhyolite lava-flow based on the volcanic character of the area. The rocks have essentially been cooked over the ages causing the unique forms of erosion. We arrived at a view of the 300 foot lower falls. Back in the Bombardier, we stopped at two different overlooks, including an overlook of the 100 foot high upper falls. We next skied down to a spot at the top of the upper falls. On the way back, we stopped to ski in sunshine by the Virginia Cascades. Here the snow was sticky and I was tired after four days of skiing. I struggled to finish the ski.