Sounds like a great trip! Thanks for the CG reports on the way, as well as in the park (YNP). We also enjoy state parks; glad you got a good sampling along the way.
You indeed got lucky to see that grizzly and her 3 cubs; postings in the last couple days on Yellowstone employee sites indicate that one of the cubs has already disappeared. Grizzlies are more commonly seen now than they were in the 60s & early 70s; I worked in the park 3 summers and only partway thru my 3rd year did I see a griz. (Saw plenty of black bears in those days; now it's more rare.)
"Death in Yellowstone" is a good book but a harrowing read. I think parts of it should be required reading for some visitors to the park (ahead of time). :)