Insite to Crossunder passage at Madison

[fghray1]

Me and Jeno have been exploring the passage for the last couple of weeks.
Went to the "T" where it drops through the floor last week. Went back today and dropped down throught he hole and went down stream for about 500 ft. Max depth was about 120 ft.
I noticed a line on the way in today that seems to run parallel to the crossunder line. Best guess is it was about 450 ft from the from the sign. Lines not easy to see, it's through a hole in the wall and runs in both directions.
Does anyone have any idea where it leads in both directions? I'm going to find out next week and was wondering what to expect. I can't see to find it on any map.
Fred

[fghray1]

Seeing as how no one could answer my question. I'll put as much insight as I found.
Went there Sat. did the jump to the line. Headed down stream and the line ended after 20 ft. Looking me in the face was the main line in the crossunder. Headed down stream and went about 200 ft. and came to a tight spot with a duck under. Walls didn't look real good, the line was wrapped around a thin column 3 in. in dia. I touched the wall to see how soft the stone was and a piece broke off. At this point the line took a right turn and the silt had piled up in the corner. I poked my finger in the silt in the middle of the passage and it sunk all the way in. I was hoping to hit sand. Being the walls were soft the silt was deep and the passage was low, not to mention it was a siphon prudence dictated we go no further. I think this goes to a jump off the Godzilla line that no one ever goes down on the right hand side. Not sure but I'm going to check it out from that side next time.