We scouted out the idea of starting our paddle at Babcock Park to go down the Yahara but it requires going through locks immediately upon launch. There is a downstream park Jaeger Park that eliminates the need to figure out how to go through the locks. We heard there is a way to portage around it, but the solution was not evident.
This map shows the relationship of the launches in the area.
Conclusion:
Although it looks inviting to put-in at Babcock Park to paddle down the Yahara to Mud Lake and exit at Fish Camp, it was not for us.