There’s an access by Anderson Windows open to the public! Or is that the power plant? Long haul for sled.
I just use the park in Bayport. Park in the overflow parking just a few hundred yards South from the beach. Or you can haul stuff down the beach. If you want to drive onto the river, when ice is thick enough, there’s a sign and directions right there in the park to tell you how to get onto the river. The access is on the south end of town just crossing the RR tracks.