So I completed my migration back to the Park.
Migration involves travel, but is not the same as "traveling". Mere travel is just going from one place to another. Migration is repeated traveling over the same path to the same destination and back to the starting point. Unlike ordinary travel, a migration also includes the expectation of the same events with the same outcome. You aren't inclined to take a side trip on a whim while migrating, because that's will only delay your arrival at your destination. If you need a road atlas, it's not a migration.
A migration is also infrequent. Do it often enough, and it qualifies as a "commute".
So how did my migration go?
Except for the frequent rain showers (which turned to snow at the Old Faithful area) and the strong headwinds in the upper Madison Valley, it was the most uneventful trip that I can remember. The time flew by, and absolutely nothing went wrong. Even after all these years, very little seems to have changed along the route, other than Missoula has continued to bloat out to the northwest.
Now it's time unpack and get everything set up and to rest up for a full day of geyser activity tomorrow.