Wind. The wind was almost straight from the south; when we checked it was 21 mph officially. We were hearing West-SouthWest so it was a crosswind mixed with a bit of headwind.
Abby took a great video of bird attempting -- and failing -- to fly into the wind.
We did this in shifts, so we each did about 70 miles. I did the first shift with Beth and the last with Abby. Because we were going so slowly and the distance was large, we started at 6:40 a.m. and finished a bit before 8:00 p.m. We were too tired to go out to eat, so we ordered pizza in.