We put our kayaks in at Blue River State Recreation Area, between Milford and Dorchester on Highway 15. It's a rather steep trail for about 15 feet, but not the worst I have seen.
The particular section of the Blue River we paddled was not very fast moving. It is full of fallen trees and sand bars, but not difficult to paddle around. There is a section where a bridge has fallen in the water leaving one spot for a tight squeeze past. If the river had been any lower we would have had to portage around it. We pulled out at a bridge near the intersection of road 1600 and B. There is no real trail, you have to walk through tall grass.
We saw tons of wildlife including sandhill cranes, owls, deer, bullsnakes, carp jumping out of the water, muskrats, wood ducks and more. Unfortunately the water is opaque and mud brown that you can't see into it at all. The mud and silt are so bad that in areas of the bank I sank knee deep in black mud.
In general this was a very pleasant trip. In a kayak at good speed it took a little over one hour.
probably a NE state park permit for your vehicle