Thanks to Steve for the following report.
I had a chance to get in a couple hours of fishing the day after Christmas. Fished upstream from Big Falls Road, experimenting along the way, and after figuring out how to get a bead head pheasant tail close to the bottom, landed a small brown, about 7 inches. The fish was pale, the par marks were very visible, the spots were brilliant red, and the adipose fin was bright orange/red. A beautiful fish indeed. And thanks for helping with selecting my gear. The Simms Rivershed waders and Cloudveil wading boots are perfect. As someone who has only wet waded in the summer, I can say that I will definitely be taking advantage of Winter fishing on the Gunpowder.