This is 18.2 miles per Google and has some great river views and some contrasting landscapes. The Mendota/62 bridge bike trail is a bit on the narrow side but not bad.
We originally planned to take the Big Rivers Trail to Mendota but it was washed out. The other alternative would have been Lilydale to Saint Paul but it was flooded. This was plan C but it was a happy reroute. I'd do it again.
Google Maps Route