We were in that area base camped on Gun the middle of August. We thought about leaving Gun through the river on our way back to the EP.we did a day trip to recon the river and found it virtually unpassable. Very weedy and very shallow. We on,6 made i5 in a couple hundred yards and turned around.
Your mileage may vary but with two guys in a fully loaded canoe it looked like more than we wanted to take on.