I'm assuming you mean the Conewago that flows eastward across northern York County (the stream that flows through York city is Codorus)?
If so, that is a warm water fishery and isn't stocked with trout. There are stocked trout upstream in Adams Co and some will wash down this time of year.
I fish it a good bit: It's a decent fishery for rockies, RB sunfish and SMBs (numbers, not size). However, in my experience, the WW species migrate out of much of that watershed seasonally, I recommend you focus on it in summer and early fall.
It's worth exploring if WW species are your game. Deeper, slower water will likely be the most productive.