September 18-20. We arrived in Yellowstone in the middle of a thunder snowstorm, and ended the day pulling a trailer over the Continental Divide and on to a dark, potholed road covered with slush and monster RVs creeping along at 5 mph. We crawled into our bunks and awoke to 25 degree weather, a pattern which persisted for our whole time there. Since our trailer probably has an R-value of 1.3, we started keeping our clothes in our beds, pulling them on in the morning, and then jumping into the truck to find a warm restaurant until the sun heated the park.
Greta was amazed by the variety of things and experiences at Yellowstone – big landscapes, wildlife (bison everywhere, often causing traffic jams), geysers, waterfalls, tourists, architecture – but no bears (although a grizzly had been spotted in our campground the day before we arrived).

Isa Lake, which sits right on the Continental Divide, and which drains to both the Atlantic and Pacific

Very large elk, which we pleased was behind a big log fence. However, the next day we saw him hop that same fence quite easily.