yes and no.
If I were to ride my bike there:
Jail trail to the hot metal bridge.
cross over the street and take the south side trail
to the end, then ride the dirt road/rocks to sand
castle lot. Either take the pedestrian stairs, or
the sidewalk or the road on the glenwood bridge.
Cross the glenwood bridge back tot he northside of
the mon river. Immediately across it, turn left
onto a dirt road/path. Cross under bridge and
across like 6 sets of tracks. you will see the
end of the the other "secret jailtrail" there.
Follow this to duck hollow, where you come to
a parkinglot, then keep riding past that on dirt
roads (allegedly old second ave) carrie furnace
will be on your right.