Re: Hypothetical question for the GSMNP natives
If you just want to catch fish, I would start at the first one-lane bridge above Tremont and fish all the way up to the Lynn Camp trailhead.
If you want a Brookie, I would go above the Chimney's picnic area, find a parking lot and start fishing.
If you want a Brown, I would go to the NC side, because I struggle to catch Browns in the Little River. It can be done, most likely around Metcalf.
Don't doubt the green weenie. Fish it as a dropper or with an indicator. It can catch all three species.
Good Luck! (hypothetically, that is...)