This is a remote area and trail is not used much. I saw one track made since the last rain. Bridge is fine to ride over with a little jump at the west end. I never imagined a lift bridge in this area.
The tunnel curves and after a 100 yards the entrance is no longer visible, so it is totally dark. I was alone, and even with a good headlight I got spooked and turned around. I spoke with a local fisherman who said the tunnel was open all the way.
The adjacent park isn't maintained very well, but looks safe.

Luck would have that Handicap parking is at Trail grade at the west end. Otherwise it is a steep though short climb from the park below. The trail surface across the ties is a steel reinforcement web making a smooth ride. However at the east end the dirt has washed away and the web is not bent down over the side of the RR tie. This cut the side wall of my tire. Luck again, it did not blow out until an hour later after loaded it back in my Van. If the web reinforcement was hammered down, it would cure this hazard. Noel Keller 21 Jun 2013