The road (car road) into Greenbrier Ranger district was closed for about 2 weeks in August from the ranger station up for them to do work on the roads (i think they replaced a culvert/bridge going up porters as well.) So really this was "Re-opening" day because no one was able to fish up there for those 2 weeks...at least without a SERIOUS hike.
The road used to open pretty much to ramses branch, but that was changed long ago. Some of the older topos still indicate the road going further up. A glance at the parks trail map will show you where you can currently drive to.