I visited the tunnel today (7-10-17) and hiked above to the right side where the rock drainage wall is. There is major erosion over the portal (10-20 ft) where all you can see is dirt over the arch of the brick. I'm not any kind of engineer but I do not thing the northern portal is going to be up much longer with the way the water drains.
Visited the tunnel on 1-20-2016. It had been raining all day and there were numerous spots on the interior where the water had worked it's way down through the rock and was pouring like a small waterfall through the cracks in the rock. The entire interior of the tunnel is all bare, exposed rock and some of it has cracked and fallen in over the years. Nothing major, but just some broken off chunks from the roof and side walls. The North entrance has some shallow standing water that seems to be there pretty much all the time. Waterproof mud boots will be sufficient and the water only extends for about 100 feet or so into the entrance and then it's dry. At the South end, you can see that there has been past efforts to secure the ceiling and walls through the use of wire mesh rebar and concrete. I did see some rock bolts that have been there a LONG time so I'm guessing that these efforts were probably made at the end of the tunnel's useful life. The efforts looked rather half-hearted and only extended for about 100 feet into the South entrance. There is a large section of the rebar mesh that never got concreted and is coming loose from the ceiling.
It seems that many years ago, a fence was placed across the South entrance, but I'm guessing that dates from the original closing of the tunnel in the early 1980's. It is no longer there and only a few remnants of it remain.
This tunnel is quite unique and should be preserved for future generations in some fashion. There were several beer cans and old tires among other garbage left for visitors at the North entrance.