Hey Dan I live in Maryville and fish the park a lot. I have camped and fished at cs 17 (the elevation there is about 1300 ft). It is better for Smallmouth at 17 than trout. Big water in there. Campsite 1 isn't close to any fishable water really. To be honest the pickings are pretty slim as far as trout goes on the Southwest corner of the park where we are close to. The elevations are generally lower than most of the park and the water warmer. Abrams Creek above 17 the trout start getting more plentiful but not much till you are above Abrams falls. I have had the best luck finding trout in the Southwest side of the park once the stream elevation gets above 1500 ft or so but not many spots that high over in there that are easily accessible.
Feel free to email me at adam dot s dot beal @ gmail if you want. I agree with Rog Elkmont area is probably the closest prime trout area to us.