Yeah, I fish the Gunny...usually wait til June when the freestones get warm. Then I hit Codorus, the Gunpowder and Clarks.
Muddy Creek is a transitional freestone. Meaning, it warms in July/August and trout migrate to cool spots, sometimes to tribs and line up, sometimes up the tribs and some to underground spring areas. Conversely, in the winter and early spring, the temps often do not rise above the ambient daytime highs until late May. or a long warm spell. (we have not had one yet...) So the water is c-c-cooold. Trout only maintain in temps like this. Thats why we are not catching alot of wild fish yet this year so far. Keep in mind also that the stocked trout from the state have NEVER felt a 40 degree water temp. They are in shock until the temps get into the 50's.
There are holdovers though. We catch them every year. And we also run into quite a bit of wild fish that come in from the tributaries to the big creek to feed in late spring and fall.
You have to remember that Muddy is not a spring creek or tailwater. It is a large freestone running west to east so the sun is on it from daybreak to sunset. (except on the bends, hint) Do a lot of walking, look for the shadowed or shaded pools, bumpy water and deeper holes. There are plenty of fish in the system. There is also ALOT of dead water. (long, slow pools knee deep).
When I fish new water I like to walk it, look into the holes, walk through a few pockets, see if I can spook a fish or two to see what kind of habitat the attract to in the stream. Then I fish it.
One of the best ways to find where fish hold in a stream is with streamers. Even if you are not hooking them, remember where they were. They will be there in May too.
Muddy Creek is also not a "round boulder" stream. It sports "tabletop sized" & "toombstone sized" flat rocks in the pocket water we call graveyards. A walk along the creek will show you many of these. Usually on the bends. Fish love these areas and hide below the corners of the flat rocks to get out of the sun. (Stream is too wide for the canopy). A walk downstream on the inside track pitching streamers is a good technique. Vary your retrieve. Swing, twitch, strip, etc.
You'll do OK, take the advice and have confidence. If ya get skunked, well, consider it dues...you'll appreciate the investment someday.
Maurice