From right in the heart of Gatlinburg, I would probably say take the bypass around to the Sugarlands Visitor Center then take a right towards Elkmont/Cades Cove. I think it's about 18 miles or so from the Sugarlands to the Townsend Y where you will take another right. LRO is a couple of miles from the Y on the right just past the Trillium Cove shopping center. If you reach the Visitor's Center (on the left) you've gone too far.
The other option would be to go back through Pigeon Forge and hang a left on US Hwy 321 and go through Wears Valley. At the light where 321 hits Townsend, take a right and LRO will be on your right a few blocks away.
Fly fishing - it's cheaper than a bass boat!