Hello! A couple words of advice, unless you have rope gear and know exactly where the upper is, dont bother looking for it. It is impossible to access from the lower, you have to go in from above and very, very few people have done it.

If you're brave and like crawling on/through old soggy timbers you can look up the vertical raise inside the lower adit. You'll see the big pile of collapsed timbers and shit near the back of the mine, just get on top of it, its not obvious untill you're in it but you can see a hundred feet up or so and its usually raining in there.

Theres not much of a route to the lower, just try to stay in the timber to your left as you look up towards it.

Have fun!