>>RLeeP,
Spring Creek (near Corry) is North of Oil and Titusville, not East. >>
Well, yes. That's what I said. East of Corry. I referenced the watershed's directional relationship to Corry, not Titusville.
I'm sorry if I was less than fully clear about that.
Additionally.. You'll need to clarify this a little bit before I can decide if I agree:
>And there are plenty of good streams flowing into the Tionesta from the South. I get the feeling your comments are pointed at, in particular, Salmon Creek and The Branch. Those streams have nice structure and stay cold, but they aren't that good due to water chemistry I guess. So if thats what you were referring to, you are spot on, but I wouldn't expand that to include other streams coming from the south.>
The section of Tionesta Creek I'm referring to is pretty much from Lynch to Nebraska Bridge. Like the majority (there are a few exceptions) of the Clarion drainage, this area has some of the poorest buffering capacity in Pennsylvania, as I understand it and the streams here are (on average) notably less fertile than those of the upper Tionesta watershed and the direct tribs of the river. So, yes this would include the Salmon Creek drainage as well as Blue Eye. The Coon Creek watershed is supposed to be a little better, especially since some residual AMD there was cleaned up. But still, my understanding is that even it is relatively infertile even by ANF standards.
For the most part though, this increased infertility is not so pronounced that it precludes the area from having a number of pretty good wild ST fisheries. I should have said that in my original post.
The Clarion drainage (again as a general rule of thumb) is pretty much the same as these lower Tionesta tribs. In his book "Rivers of Pennsylvania", Tim Palmer notes that there are many first order streams in the Clarion basin with low flow PH's in the mid 5's. This leaves virtually no room for additional acidification before even brook trout cannot make it. Again, there are exceptions. The upper WB Clarion watershed was improving a good deal the last I looked into it and both BT and ST reproduction were up. So too with portions of the Spring Creek drainage. But by and large, streams like Maple, Millstone, Mill, Bear, even Spring and most of their tribs of significance are not and historically have not been good producers of wild trout, although as I recall from time to time brook trout pops build up relatively well in Upper Bear for example before crashing again.
I probably also should have originally noted that there are a number of good wild trout streams in the upper Tionesta basin, especially among the tribs of the West Branch. Maybe some of them enter from the south, I dunno...