I haven’t been up there yet, but it has the reputation of being very rugged. Some people do not recommend going there alone.
Steve is right on fishing in the park in the winter. Most people have some success drifting nymphs through deep pools on rivers at lower elevations.
Personally, I’d wait until Spring for that particular trail/creek if fishing was a primary concern. Better fishing and less dangerous.
You might try to contact Jim Casada or buy his book on fishing the park to get some more information. Nice man and a great resource for information on the park’s waters.
Definitely interested in a trip report if you do go.