Nathan and I did the same thing you did at Sycamore. Caught lots of tiny rainbows and no Brookies. We then went to the hatchery and spoke with the TWRA folks (one guy was in the youtube video talking about the restoration) who told us we needed to go up further and it was easier to access from the top end. Where it first hits the gradient and loses the trail he said were some, but going further up was the recommendation.
I need to learn this area better