few things. I definitely agree with the comments of SB, Swattie, and TB that Jeans Run is too remote and steep and just overall hairy to mess with in the winter. As TB notes, rescuers could have an awful time getting in there and the nighttime lows are nothing to mess with this time of year. Through some combination of stupidity, luck, and experience with the ways in and out, I have fished it in the winter before.. but I wont fish it either alone or in the winter any more.
The gradient was mentioned, yeah the stream seems like 50%, but if you get out a topo it has about 10% grade over its steepest half mile. 10% doesn't sound like that much, but any stream with 10% grade in a half mile is very steep. There is a section of Jeans with a 60 ft drop at about a 20% grade (60 ft drop in 300 ft of stream course), and that signals a waterfall or waterfalls.
Slope/gradient is worth a look when considering steep streams. (I do this with a detailed garmin gps topo map). I recently was taken to a tiny stream I didn't know, and didn't bother to check the gradient. Turns out to be 10% over a half mile, and it was very steep -- so the climbing got hairy even though the stream is really quite small. Had a blast, but don't think I'd do it solo.
Most PA streams don't have a 10% grade over a half mile. The steepest PA stream I know is glen onoko, which has a 25% grade over a half mile -- that's going to be waterfalls more than stream. also many people have been hurt there. I would never try to fish it or even hike it.
One stream classification system counts streams over 10% as the steep ones, which says something. A stream with 7% grade in a hlf mile, such as stone run in Wyoming county, is actually quite steep.
I know the stream type system linked below isn't some universal std, but when a PA stream has 10% grade over a half mile, or has a 60ft elevation loss in 300 ft or less of stream course (so a 20% slope/grade), it's a good candidate to fish with buddies and leave alone in the winter imho...
