The town of Taos was on the west bank in Navarro County, that info is correct. The actual "bluff" is on the east side and is very apparent when viewing the site. According to an archeological report done in 1972, foundations and other signs of buildings, as well as a cemetary site, were located on the east side of the river, on the bluff in Henderson County. The original land grant given to Porter was on both sides of the river, so the theory is that after the big flood in 1866 destroyed most of the original town of Taos, some of the rebuilding was done on the opposite bank up on the bluff. That would seem to coincide with the name change from Taos to Porter's Bluff. There were foundations on the west side that were destroyed when the modern bridge was built in the 1950's. No definitive history of this town exists as far as I know, but I am trying to piece it together.
The Porter's Bluff-Tyler road generally followed the route of Highway 85, and curved slightly to the south somewhere near Seven Points. As far as I know, there are no remaining traces in that area. At some point that is now underwater, it crossed the Tool-Mabank road ( modern day Arnold Hills Road ) and continued towards the Eustace area. A trace is visible at the south end of Purtis Creek State Park. There was another vanished town in that area, Big Rock or something like that. From there it continued on to Edom and Tyler. There was also a road from Porter's Bluff to Corsicana. There was another one, probably more of a trail than a road, than ran northwest from Porter's Bluff to Ft. Worth.