Mark--your pictures of the South Rim with snow on the ground bring back some great memories. The Grand Canyon is amazing, all year around, but when there's weather, or seasonal changes, it's that much more impressive.
My favorite side of the canyon, personally, is the North Rim, which gets just 10% of the crowds. It's closed in winter, unfortunately, but the last time I was up there was in the Autumn, a week before the seasonal shut down. The road in from Jacob Lake is lined with aspens that were turning to gold:
and there were more trees turning color along the canyon rim.
All of that made for a very special visit!
It's in the book, of course: Scenic Side Trip #13: St. George, Utah to Flagstaff (by way of Zion National Park, the North Rim, and Page).
Rick
Read more about Rick's book here and see a map for all of the routes he wrote about.